title: Kevin Macdonald (director)

text: Macdonald worked with the film production team Altitude, who created the commercially and critically acclaimed Amy Winehouse documentary film "Amy" (2015), on "Whitney", a 2018 documentary based on Whitney Houston's life and death. This was the first Whitney Houston documentary to be officially authorized by the estate, and includes never-before-seen footage of Houston, exclusive demo recordings, rare performances and interviews with luminaries like Clive Davis. Macdonald stated, "The story that is never told about Whitney is just how brilliant she was as an artist; by many measures she had the greatest voice of the last 50 years. She changed the way pop music was sung - bringing it back full circle to its blues and gospel roots. She was also completely unique in being a black pop star who transcended her race globally with her work sold in countries where black artists don't sell."


title: Kevin Macdonald (director)

text: In 2021, Macdonald released "The Mauritanian", a legal drama based on the true story of Mohamedou Ould Slahi, a Mauritanian man who was held for fourteen years (from 2002 to 2016) without charge in the Guantanamo Bay detention camp, a United States military prison. The film received mixed to positive reviews, with critics praising Macdonald's direction, its cinematography and performances of the cast but criticised its screenplay. At the 78th Golden Globe Awards the film received two nominations; Best Actor – Motion Picture Drama (for Rahim), with Foster winning Best Supporting Actress – Motion Picture. At the 74th British Academy Film Awards the film received five nominations, including Best Film.


title: 2021 Baltimore Ravens season

text: The 2021 season was the Baltimore Ravens' 26th season in the National Football League and their 14th under head coach John Harbaugh.


title: 2021 Baltimore Ravens season

text: Several NFL records were broken or achieved by the Ravens this season. On August 23, the Baltimore Ravens and John Harbaugh claimed the record of consecutive preseason wins with 20, overtaking Vince Lombardi’s Green Bay Packers record with a win over the Washington Football Team. On September 26, placekicker Justin Tucker broke the NFL record for the longest field goal in history, kicking a 66-yard field goal as time expired to beat the Detroit Lions 19–17. The next week, on October 3, the Ravens tied the record for most consecutive games rushing over 100 yards as a team with 43 (tied with their division rival Steelers) in a 23–7 win over the Denver Broncos.


title: 2021 Baltimore Ravens season

text: However, despite starting the season 8–3, the Ravens suffered a late-season collapse, ending the season with a brutal six game losing streak in which five of the losses were by a combined 8 points, including two of the five losses as a result of a failed two-point conversion late in the fourth quarter, and failed to improve on their 11–5 record from last season after a Week 15 loss to the Green Bay Packers. The Ravens also suffered their first losing season since 2015, finished last place in the AFC North for the first time since 2007, and were eliminated from the postseason for the first time since 2017 after a loss to the Steelers in Week 18. It was the first time in the Lamar Jackson era that the Ravens failed to qualify for the postseason.


title: 2021 Baltimore Ravens season

text: The Ravens suffered many injuries to key players throughout the season, including losing J. K. Dobbins, Gus Edwards, Justice Hill, L. J. Fort, and Marcus Peters to season-ending injuries before the regular season started, and losing Ronnie Stanley, Marlon Humphrey, Derek Wolfe, DeShon Elliott and more during the season, while quarterback Lamar Jackson missed the final four games of the season due to an ankle injury. The Ravens ended the season with a league high 19 players on injured reserve. The year was also only the second in Ravens history to not have a Pro Bowler on defense, the other being 2005.


title: 2021 Baltimore Ravens season

text: The Ravens' 2021 schedule was announced on May 12. Apart from their AFC North division games, the Ravens played games against the AFC West and NFC North in accordance with the NFL's schedule rotation. They also played against the Indianapolis Colts, the Miami Dolphins, and the Los Angeles Rams, who finished 2020 in the same position as the Ravens in the two other AFC divisions and the NFC West, which the Ravens would play fully in 2019 and 2023.


title: 2021 Baltimore Ravens season

text: The Ravens blew multiple fourth quarter leads and lost in overtime 27–33 to the Raiders on Monday Night Football.


title: 2021 Baltimore Ravens season

text: The Raiders received the opening kickoff and moved into Baltimore territory before a shotgun snap that was not expected by Las Vegas quarterback Derek Carr led to a 15-yard loss. As a result of the play, the Raiders were forced to punt. The Ravens were unable to do much with the ball and punted as well. A three-and-out series by the Raiders gave the ball to the Ravens at their own 35. The Ravens moved into Raider territory, but were faced with a fourth and one at the Raider 35-yard line. Ty'Son Williams broke through the line on the fourth down play for a 35-yard touchdown run to give Baltimore a 7–0 lead. The teams exchanged punts on their next possessions before the Ravens moved into Raider territory again. Lamar Jackson hit Marquise Brown on a 10-yard touchdown pass with nine minutes remaining in the second quarter and it appeared the Raiders might get blown out. However, on the ensuing possession, Carr was finally able to connect with tight end Darren Waller and move the ball to the Ravens two-yard line before Josh Jacobs scored to cut the lead in half, 14–7. The Ravens again moved into Raider territory with less than two minutes left in the half, but were stopped short on fourth down and turned the ball over to Las Vegas. Carr quickly moved the Raiders to the Baltimore 14-yard line, but had to settle for a Daniel Carlson 34-yard field goal as the half ended leaving the score 14–10 at halftime.


title: 2021 Baltimore Ravens season

text: In the second half, the team exchanged punts again before the Ravens connected on a 40-yard field goal by Justin Tucker to move the lead back to seven at 17–10. The Raiders looked to answer by moving in to Raven territory, but were stuffed on a fourth-and-one at the Raven 13. The teams again exchanged punts as the game moved to the fourth quarter. The Ravens took over with 13:23 remaining in the quarter, but Jackson scrambled and had the ball knocked out of his hands and fumbled with the Raiders' Denzel Perryman recovering the ball at the Baltimore 41. Four plays later, Jacobs scored on a 25-yard run to tie the game at 17. The Ravens quickly answered as Latavius Murray scored on an eight-yard touchdown run to give the Ravens a 24–17 lead with about six minutes remaining. Carr moved the Raiders down field and, with just under four minutes left, hit Waller for a 10-yard touchdown pass to again tie the game. Baltimore responded by moving into Raider territory, but were unable to get a first down on a third-down play at the Vegas 31 and were forced to settle for a field goal with 37 seconds remaining. Carr, with no timeouts, hit Bryan Edwards for a 20-yard gain on the first play of the ensuing possession. After a spike to stop the clock, Carr hit Edwards again for 18 yards to move the ball to the Raven 37. Carlson then hit a 55-yard field to tie the game at 27. With two second remaining in the quarter, the Ravens took a knee to settle for overtime.


title: 2021 Baltimore Ravens season

text: In overtime, the Raiders won the toss and moved into Raven territory on a pass by Carr to Hunter Renfrow. Renfrow appeared to step out of bounds at least once on the 27-yard play, but no review was made. Two plays later, Carr, backpedaling to avoid the rush, threw a 33-yard touchdown pass to Edwards to apparently win the game. As players celebrated on the field, the play was reviewed and it was determined Edwards was down near the one-yard line, overturning the touchdown. After clearing the field, Carr was stuffed on sneak attempt. Rookie right tackle Alex Leatherwood then committed a false start penalty and the ball was moved back outside the five-yard line. Following an incompletion, Carr's next pass went through the hands of Willie Snead and bounced off a DeShon Elliott's helmet before being intercepted by Anthony Averett in the end zone for a touchback. After the Ravens took over at the 20, Jackson fumbled again which was again recovered by the Raiders. Following a one-yard run to the Ravens' 26, the Raiders belatedly decided to attempt a field goal. However, due to the slow decision, Carlson did not get on the field in time and the Raiders, who had used their two timeouts on the prior possession, committed a delay of game penalty. Jon Gruden decided to not try the field goal on the next play and Carr, under pressure and backpedaling, threw to a wide open Zay Jones for a 31-yard touchdown to end the game.


title: 2021 Baltimore Ravens season

text: With the heartbreaking upset loss, the Ravens fell to 0–1 for the first time since 2015. This game marked the 12th game with an upset in Week 1 during the 2021 NFL season an NFL record.


title: 2021 Baltimore Ravens season

text: The Ravens overcame two 11-point 2nd half deficits to stun the Chiefs 36–35 on Sunday Night Football, avoiding an 0–2 start. Lamar Jackson ran for two fourth quarter touchdowns on consecutive drives, overcoming two first quarter interceptions, the former of which was a Pick 6, by Tyrann Mathieu. Kansas City then drove into field goal range, but rookie outside linebacker Odafe Oweh forced and recovered a fumble by Clyde Edwards-Helaire at the Baltimore 34-yard line with 1:20 left to go in regulation. The Ravens then forced the Chiefs to use all 3 of their timeouts before Jackson sealed the win with a 2-yard run on 4th and 1 from the Baltimore 43. It was Jackson's first ever win over Patrick Mahomes in four tries as well as the largest deficit he's overcome in his career. It was also the Ravens’ first win over the Chiefs since their 2012 Super Bowl season. With the win, the Ravens improved to 1–1.


title: 2021 Baltimore Ravens season

text: The Ravens survived a fourth quarter rally by the Detroit Lions to win 19–17 at Ford Field. After trailing 7–16 going into the fourth quarter, the Lions scored 10 unanswered points, taking the lead with 1:04 left to play on a Ryan Santoso 35-yard field goal. On the ensuing possession, the Ravens faced a 4th & 19 deep in their own territory with less than 30 seconds to go, but Lamar Jackson found Sammy Watkins for a long gain out to the Lions 48 yard line. After spiking the ball, Jackson took four more seconds off the clock by throwing the ball out of bounds, leaving only three seconds on the clock. However, the referees missed that the play clock expired before the play, which should been a five-yard penalty for delay of game. Longtime Ravens kicker Justin Tucker, who missed a 49-yard field goal earlier, then hit an NFL-record 66-yard field goal as time expired to win the game. With the win, the Ravens improved to 2–1.


title: 2021 Baltimore Ravens season

text: Facing a 0–7 deficit after a slow start, the Ravens rattled off 17 second quarter points and defeated the Denver Broncos 23–7 for their third straight win. Lamar Jackson threw for 316 yards and a touchdown, his first 300-yard passing game since Week 1 of the 2019 season, while adding 28 yards on the ground. The Ravens also tied the record for most consecutive games rushing over 100 yards as a team with 43 (tied with their division rival, the Steelers) with a 5-yard run by Jackson on the last play of the game. With their third-straight win, the Ravens improved to 3–1.


title: 2021 Baltimore Ravens season

text: Trailing 3–22 late in the third quarter, the Ravens scored four touchdowns in as many drives to defeat the Colts in overtime 31–25 on Monday Night Football. Lamar Jackson had 442 yards passing, both a career high and franchise record, and four touchdowns while adding 62 yards rushing. The Colts also had a field goal blocked with 4:37 left in the fourth quarter and missed a potential game winner at the end of regulation. It was the largest deficit (19 points) that Jackson had overcome in a game, beating out the 11-point deficits he overcame against the Kansas City Chiefs earlier in the season. With their fourth straight win, the Ravens improved to 4–1 and moved into first place in the AFC North due to losses by both the Cleveland Browns and the Cincinnati Bengals.


title: 2021 Baltimore Ravens season

text: The Ravens used dominant offensive and defensive performances to rout the Chargers 34–6. Baltimore rushed for 187 yards and three touchdowns while the defense held the Chargers to just 208 yards of total offense and only 26 rushing yards while holding the ball for over 38 minutes. The victory was Lamar Jackson's 35th as a starter, setting the record for the most wins by a starting quarterback before their 25th birthday in NFL history, surpassing the previous mark of 34 set by Dan Marino. With their fifth straight win, the Ravens improved to 5–1.


title: 2021 Baltimore Ravens season

text: The Ravens five-game win streak along with their five-straight wins over the Bengals came to a brutal end as the Bengals scored 28 unanswered second half points and routed them 17–41. The Bengals outgained the Ravens 520–393 and had five sacks as Baltimore was 1 for 4 on fourth downs in the second half. It was the Ravens worst home loss since a 6–35 loss to the Seattle Seahawks in Week 14 of the 2015 season and the first time they've lost at home to the Bengals since Week 17 of the 2017 season. It was also Lamar Jackson's worst loss in his career as well as his first lost in the month of October, and his first loss to the Bengals. With the loss, the Ravens dropped to 5–2 and entered a tie with the Bengals for 1st place in the AFC North.


title: 2021 Baltimore Ravens season

text: The Ravens overcame a slow start, two 14-point deficits, and an overtime interception to defeat the Minnesota Vikings 34–31 in overtime. Trailing 3–17 late in the second quarter, the Ravens scored touchdowns on four consecutive long drives to take 31–24 lead late in the fourth quarter behind three touchdown passes by Lamar Jackson and a touchdown run by Le'Veon Bell. However, the Vikings then drove down and tied the game at 31 on an Adam Thielen touchdown reception from Kirk Cousins, his second touchdown pass of the game. In overtime, the Ravens won the toss and drove into Vikings territory, but the drive abruptly ended when a pass by Jackson was tipped and intercepted by Anthony Barr. The Vikings were unable to capitalize, however, as they went three and out and punted the ball back to the Ravens. Needing only a field goal to win, the Ravens again drove into Vikings territory and won on a 36-yard field goal by Justin Tucker. With the win, the Ravens improved to 6–2.


title: 2021 Baltimore Ravens season

text: The Ravens offense struggled to get anything going against the Miami Dolphins, resulting in a stunning 10–22 upset loss on Thursday Night Football. After the first two drives ended in field goal attempts, the second of which was missed, the Ravens failed to score on nine consecutive drives, with seven of them ending in punts, one ending with a lost fumble by Sammy Watkins – which was returned by Xavien Howard for a touchdown –, while one ended by the end of the first half. Meanwhile, the Dolphins scored 15 unanswered points and held off a late comeback attempt by the Ravens to win their second straight game. With the loss, the Ravens fell to 6–3.


title: 2021 Baltimore Ravens season

text: Playing without star quarterback Lamar Jackson due to an illness, the Ravens behind second-year QB Tyler Huntley rallied in the final minute to defeat the Chicago Bears 16–13. Earlier in the week, Jackson had designated as questionable due to an undisclosed non-COVID illness. He was removed from the injury report that Friday, but was reinserted on it the next day when his condition abruptly degraded before being ruled out on gameday. Without Jackson, along with wide receiver Marquise Brown, the Ravens struggled to move the ball, but were able to do just enough to take a 9–7 lead late in the fourth quarter on a Justin Tucker 46-yard field goal. On the ensuing drive, however, Andy Dalton, who was in for Justin Fields after the latter suffered a rib injury in the third quarter, threw his second touchdown pass of the day to Marquise Goodwin from 49-yards out on 4th and 11 with less than 1:45 left to go in regulation. Trailing by four after the Bears failed on the two-point conversion, the Ravens quickly drove down the field and retook the lead on a Devonta Freeman 3-yard run touchdown run with just 0:22 to go. The Bears were unable to get into field goal range on their final drive and Dalton was sacked by Tyus Bowser before the former could get off a hail mary throw on the last play of the game. It was the first time the Ravens had defeated the Bears at Soldier Field (they were 0–3 in the stadium prior to this game). With the win, the Ravens improved to 7–3.


title: 2021 Baltimore Ravens season

text: Lamar Jackson and the Ravens overcame four interceptions, including three straight in as many drives in the second quarter, and won their second consecutive game with a 16–10 victory on Sunday Night Football. The Ravens improved to 8–3 and gained control on the number one seed in the AFC.


title: 2021 Baltimore Ravens season

text: The Ravens blew a fourth quarter lead, allowing the Steelers to get 17 points before failing on a two-point conversion on a last-minute touchdown, losing 19–20. Going into the fourth quarter, the Ravens led 10–3, but the Steelers outscored them 17–3, taking a 20–13 lead on a Ben Roethlisberger touchdown pass to Diontae Johnson along with a two-point conversion. The Ravens then quickly drove down the field and Lamar Jackson threw a short touchdown pass to Sammy Watkins with only 12 seconds left. Due to losing CB Marlon Humphrey earlier in the game, leaving them with only 5 CBs available to play, the Ravens attempted to win the game by going for two instead of tying it with an extra point. However, Lamar Jackson pass to Mark Andrews on the attempt was off-target and Andrews was unable to catch it, leaving the Ravens down by one. The Steelers then recovered the onside kick and ran out the clock. With the loss, the Ravens fell to 8–4 out and dropped from the number 1 seed to the 3 seed.


title: 2021 Baltimore Ravens season

text: The Ravens lost their second straight game as their late comeback attempt failed in a 22–24 defeat to the Cleveland Browns. The Ravens lost QB Lamar Jackson to an ankle injury in the first quarter and were down 3–24 late in the second quarter. The defense shut out the Browns in the second half and the Ravens recovered an onside kick following their second fourth quarter touchdown, but were unable to convert on 4th and 6 to get into field goal range. With the loss, the Ravens fell to 8–5.


title: 2021 Baltimore Ravens season

text: A late Ravens comeback attempt fell short due to failing a two-point conversion after a final minute touchdown in a 30–31 loss to the Green Bay Packers. Playing without QB Lamar Jackson due to an ankle injury, backup QB Tyler Huntley attempted to keep up with the Packers offensive attack led by QB Aaron Rodgers. After going into halftime tied at 14, the Packers went ahead 31–17 about midway through the fourth quarter. Tyler Huntley then led a touchdown drive to cut the lead to 7 while the defense forced a three and out. The Ravens drove again and scored again on Huntley scramble with 42 seconds left, his second touchdown run in as many drives. For the second time in three weeks, the Ravens attempted to go for two to take the lead, but Huntley's pass intended for Mark Andrews was broken up leaving the Ravens down by one. The Packers then recovered the onside kick and ran out the clock. With their third straight loss, the Ravens fell out of the playoff picture and dropped to 8–6.


title: 2021 Baltimore Ravens season

text: Down to their third string quarterback, the Ravens were unable to keep up with the Bengals offensive attack and were again blown out 21–41. QB Joe Burrow threw for 525 yards and four touchdowns with 184 yards and two of those touchdowns going to WR Tee Higgins on 12 receptions. With QBs Lamar Jackson (ankle injury) and Tyler Huntley (positive COVID-19 test) both out, recently signed Josh Johnson started for the Ravens, throwing for 304 yards, two touchdowns, and an interception in a losing effort. With the loss, the Ravens fell to 8–7 and were swept by the Bengals for the first time since 2015.


title: 2021 Baltimore Ravens season

text: The Ravens blew yet another fourth quarter lead and lost at home to the Los Angeles Rams 19–20. The Ravens took the lead on a 17-yard interception return touchdown by Chuck Clark in the first quarter, the Ravens' first defensive touchdown of the year and the first of three turnovers committed by Matthew Stafford on the day. Clark picked off Stafford again on the next drive and the Ravens extended their lead to 10–0 on the first of four Justin Tucker field goals. They went into halftime up 13–7 and into the fourth quarter up 16–7. The Rams scored a touchdown early in the quarter before the Ravens began another long drive that got them into the red zone late in the quarter. However, the drive stalled and Tucker kicked a chip shot field goal. The Rams then drove again, converting a fourth down in the red zone and took the lead thanks to Matthew Stafford touchdown pass to Odell Beckham Jr. with less than a minute to go. The Ravens were never able to get into field goal range and Huntley was stripped sacked on the last play of the game. With their fifth straight loss, the Ravens fell to 8–8. With the Steelers' win over the Browns on Monday Night, they fell to third place in the AFC North with only a slim chance to make the playoffs the next week.


title: 2021 Baltimore Ravens season

text: The Ravens were eliminated from playoff contention with a brutal loss in overtime at home against the Pittsburgh Steelers, resulting in their sixth straight loss.


title: 2021 Baltimore Ravens season

text: In the first quarter, the Steelers scored the only points when Chris Boswell kicked a 28-yard field goal to make it 3–0. The Ravens tied it up at 3–3 in the second quarter when Justin Tucker kicked a 24-yard field goal. This would be the score at halftime. In the third quarter, the Ravens moved into the lead when Latavius Murray ran for a 46-yard touchdown to make it 10–3. The Steelers then came within 4 when Boswell kicked a 40-yard field goal, making the score 10–6. The Ravens drove into the red zone on the next drive, but Tyler Huntley, who was replacing Lamar Jackson for the fourth straight game, threw his second interception of the day in end zone early in the fourth quarter. The Steelers retook the lead in the final three minutes of the fourth when Ben Roethlisberger found Chase Claypool on a 6-yard touchdown pass to make it 13–10. Tucker then tied the game up at 13–13 with a 46-yard field goal. In overtime, the Ravens won the toss, but their drive stalled, forcing them to punt. The Steelers were able to drive down the field, converting a 4th & 8 along the way, and eventually Boswell was brought out to kick the game-winning 36-yard field goal to win the game 16–13.


title: 2021 Baltimore Ravens season

text: With the loss, the Ravens extended their losing streak to six games and finished the season with a losing record at 8–9 and in last place of the AFC North for the first time since 2007. Even if the Ravens had won, they still would have been eliminated from playoff contention due to the Miami Dolphins defeating the New England Patriots 33–24 later that afternoon.


title: Amateur

text: An amateur () is generally considered a person who pursues an avocation independent from their source of income. Amateurs and their pursuits are also described as popular, informal, self-taught, user-generated, DIY, and hobbyist.


title: Amateur

text: Historically, the amateur was considered to be the ideal balance between pure intent, open mind, and the interest or passion for a subject. That ideology spanned many different fields of interest. It may have its roots in the ancient Greek philosophy of amateur athletes competing in the Olympics. The ancient Greek citizens spent most of their time in other pursuits, but competed according to their natural talents and abilities.


title: Amateur

text: The "gentleman amateur" was a phenomenon among the gentry of Great Britain from the 17th century until the 20th century. With the start of the Age of Reason, with people thinking more about how the world works around them, (see science in the Age of Enlightenment), things like the cabinets of curiosities, and the writing of the book "The Christian Virtuoso", started to shape the idea of the gentleman amateur. He was vastly interested in a particular topic, and studied, observed, and collected things and information on his topic of choice. The Royal Society in Great Britain was generally composed of these "gentleman amateurs", and is one of the reasons science today exists the way it does. A few examples of these gentleman amateurs are Francis Bacon, Isaac Newton, and Sir Robert Cotton, 1st Baronet, of Connington.


title: Amateur

text: Amateurism can be seen in both a negative and positive light. Since amateurs often do training and be self-taught, some amateur work may be considered sub-par. For example, amateur athletes in sports such as basketball, baseball, or football are regarded as possessing a lower level of ability than professional athletes. On the other hand, an amateur may be in a position to approach a subject with an open mind (as a result of the lack of formal training) and in a financially disinterested manner. An amateur who dabbles in a field out of interest rather than as a profession, or possesses a general but superficial interest in any art or a branch of knowledge, is often referred to as a dilettante.


title: Amateur

text: Through most of the 20th century the Olympics allowed only amateur athletes to participate and this amateur code was strictly enforced - Jim Thorpe was stripped of track and field medals for having taken expense money for playing baseball in 1912.


title: Amateur

text: Later on, the nations of the Communist Bloc entered teams of Olympians who were all nominally students, soldiers, or working in a profession, but many of whom were in reality paid by the state to train on a full-time basis.


title: Amateur

text: Near the end of the 1960s, the Canadian Amateur Hockey Association (CAHA) felt their amateur players could no longer be competitive against the Soviet team's full-time athletes and the other constantly improving European teams. They pushed for the ability to use players from professional leagues but met opposition from the International Ice Hockey Federation (IIHF) and the International Olympic Committee (IOC). At the IIHF Congress in 1969, the IIHF decided to allow Canada to use nine non-NHL professional hockey players at the 1970 World Championships in Montreal and Winnipeg, Manitoba, Canada. The decision was reversed in January 1970 after IOC President Avery Brundage said that ice hockey's status as an Olympic sport would be in jeopardy if the change was made. In response, Canada withdrew from all international ice hockey competitions and officials stated that they would not return until "open competition" was instituted. Günther Sabetzki became president of the IIHF in 1975 and helped to resolve the dispute with the CAHA. In 1976, the IIHF agreed to allow "open competition" between all players in the World Championships. However, NHL players were still not allowed to play in the Olympics, because of the unwillingness of the NHL to take a break mid-season and the IOC's amateur-only policy.


title: Amateur

text: Before the 1984 Winter Olympics, a dispute formed over what made a player a professional. The IOC had adopted a rule that made any player who had signed an NHL contract but played less than ten games in the league eligible. However, the United States Olympic Committee maintained that any player contracted with an NHL team was a professional and therefore not eligible to play. The IOC held an emergency meeting that ruled NHL-contracted players were eligible, as long as they had not played in any NHL games. This made five players on Olympic rosters—one Austrian, two Italians and two Canadians—ineligible. Players who had played in other professional leagues—such as the World Hockey Association—were allowed to play. Canadian hockey official Alan Eagleson stated that the rule was only applied to the NHL and that professionally contracted players in European leagues were still considered amateurs. Murray Costello of the CAHA suggested that a Canadian withdrawal was possible. In 1986, the IOC voted to allow all athletes to compete in Olympic Games starting in 1988, but let the individual sport federations decide if they wanted to allow professionals.


title: Amateur

text: After the 1972 retirement of IOC President Brundage, the Olympic amateurism rules were steadily relaxed, amounting only to technicalities and lip service, until being completely abandoned in the 1990s (in the United States, the Amateur Sports Act of 1978 prohibits national governing bodies from having more stringent standards of amateur status than required by international governing bodies of respective sports. The act caused the breakup of the Amateur Athletic Union as a wholesale sports governing body at the Olympic level).


title: Amateur

text: Olympic regulations regarding amateur status of athletes were eventually abandoned in the 1990s with the exception of wrestling, where the amateur fight rules are used due to the fact that professional wrestling is largely staged with pre-determined outcomes. Starting from the 2016 Summer Olympics, professionals were allowed to compete in boxing, though amateur fight rules are still used for the tournament.


title: Amateur

text: Many amateurs make valuable contributions in the field of computer programming through the open source movement. Amateur dramatics is the performance of plays or musical theater, often to high standards, but lacking the budgets of professional West End or Broadway performances. Astronomy, chemistry, history, linguistics, and the natural sciences are among the fields that have benefited from the activities of amateurs. Gregor Mendel was an amateur scientist who never held a position in his field of study. Radio astronomy was founded by Grote Reber, an amateur radio operator. Radio itself was greatly advanced by Guglielmo Marconi, a young Italian man who started out by tinkering with a coherer and a spark coil as an amateur electrician. Pierre de Fermat was a highly influential mathematician whose primary vocation was law.


title: Amateur

text: In the 2000s and 2010s, the distinction between amateur and professional has become increasingly blurred, especially in areas such as computer programming, music and astronomy. The term amateur professionalism, or pro-am, is used to describe these activities.


title: Hemocyanin

text: Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O). They are second only to hemoglobin in frequency of use as an oxygen transport molecule. Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not confined in blood cells but are instead suspended directly in the hemolymph. Oxygenation causes a color change between the colorless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form.


title: Hemocyanin

text: Hemocyanin was first discovered in "Octopus vulgaris" by Leon Fredericq in 1878. The presence of copper in molluscs was detected even earlier by Bartolomeo Bizio in 1833. Hemocyanins are found in the Mollusca and Arthropoda including cephalopods and crustaceans and utilized by some land arthropods such as the tarantula "Eurypelma californicum", the emperor scorpion, and the centipede "Scutigera coleoptrata". Also, larval storage proteins in many insects appear to be derived from hemocyanins.


title: Hemocyanin

text: The arthropod hemocyanin superfamily is composed of phenoloxidases, hexamerins, pseudohemocyanins or cryptocyanins, and (dipteran) hexamerin receptors.


title: Hemocyanin

text: Phenoloxidase are copper containing tyrosinases. These proteins are involved in the process of sclerotization of arthropod cuticle, in wound healing, and humoral immune defense. Phenoloxidase is synthesized by zymogens and are activated by cleaving an N-terminal peptide.


title: Hemocyanin

text: Hexamerins are storage proteins commonly found in insects. These proteins are synthesized by the larval fat body and are associated with molting cycles or nutritional conditions.


title: Hemocyanin

text: Pseudohemocyanin and cryptocyanins genetic sequences are closely related to hemocyanins in crustaceans. These proteins have a similar structure and function, but lack the copper binding sites.


title: Hemocyanin

text: The evolutionary changes within the phylogeny of the hemocyanin superfamily are closely related to the emergence of these different proteins in various species. The understanding of proteins within this superfamily would not be well understood without the extensive studies of hemocyanin in arthropods.


title: Hemocyanin

text: Although the respiratory function of hemocyanin is similar to that of hemoglobin, there are a significant number of differences in its molecular structure and mechanism. Whereas hemoglobin carries its iron atoms in porphyrin rings (heme groups), the copper atoms of hemocyanin are bound as prosthetic groups coordinated by histidine residues. The active site of hemocyanin is composed of a pair of copper(I) cations which are directly coordinated to the protein through the driving force of imidazolic rings of six histidine residues. It has been noted that species using hemocyanin for oxygen transportation include crustaceans living in cold environments with low oxygen pressure. Under these circumstances hemoglobin oxygen transportation is less efficient than hemocyanin oxygen transportation. Nevertheless, there are also terrestrial arthropods using hemocyanin, notably spiders and scorpions, that live in warm climates. The molecule is conformationally stable and fully functioning at temperatures up to 90 degrees C.


title: Hemocyanin

text: Most hemocyanins bind with oxygen non-cooperatively and are roughly one-fourth as efficient as hemoglobin at transporting oxygen per amount of blood. Hemoglobin binds oxygen cooperatively due to steric conformation changes in the protein complex, which increases hemoglobin's affinity for oxygen when partially oxygenated. In some hemocyanins of horseshoe crabs and some other species of arthropods, cooperative binding is observed, with Hill coefficients of 1.6–3.0. Hill coefficients vary depending on species and laboratory measurement settings. Hemoglobin, for comparison, has a Hill coefficient of usually 2.8–3.0. In these cases of cooperative binding hemocyanin was arranged in protein sub-complexes of 6 subunits (hexamer) each with one oxygen binding site; binding of oxygen on one unit in the complex would increase the affinity of the neighboring units. Each hexamer complex was arranged together to form a larger complex of dozens of hexamers. In one study, cooperative binding was found to be dependent on hexamers being arranged together in the larger complex, suggesting cooperative binding between hexamers. Hemocyanin oxygen-binding profile is also affected by dissolved salt ion levels and pH.


title: Hemocyanin

text: Hemocyanin is made of many individual subunit proteins, each of which contains two copper atoms and can bind one oxygen molecule (O). Each subunit weighs about 75 kilodaltons (kDa). Subunits may be arranged in dimers or hexamers depending on species; the dimer or hexamer complex is likewise arranged in chains or clusters with weights exceeding 1500 kDa. The subunits are usually homogeneous, or heterogeneous with two variant subunit types. Because of the large size of hemocyanin, it is usually found free-floating in the blood, unlike hemoglobin.


title: Hemocyanin

text: Hexamers are characteristic of arthropod hemocyanins. A hemocyanin of the tarantula "Eurypelma californicum" is made up of 4 hexamers or 24 peptide chains. A hemocyanin from the house centipede "Scutigera coleoptrata" is made up of 6 hexamers or 36 chains. Horseshoe crabs have an 8-hexamer (i. e. 48-chain) hemocyanin. Simple hexamers are found in the spiny lobster "Panulirus interruptus" and the isopod "Bathynomus giganteus". Peptide chains in crustaceans are about 660 amino acid residues long, and in chelicerates they are about 625. In the large complexes there is a variety of variant chains, all about the same length; pure components do not usually self-assemble.


title: Hemocyanin

text: Hemocyanin is homologous to the phenol oxidases (e.g. tyrosinase) since both proteins share type 3 Cu active site coordination. In both cases inactive proenzymes such as hemocyanin, tyrosinase, and catcholoxidase must be activated first. This is done by removing the amino acid that blocks the entrance channel to the active site when the proenzyme is not active. There is currently no other known modifications necessary to activate the proenzyme and enable catalytic activity. Conformational differences determine the type of catalytic activity that the hemocyanin is able to perform. Hemocyanin also exhibits phenol oxidase activity, but with slowed kinetics from greater steric bulk at the active site. Partial denaturation actually improves hemocyanin's phenol oxidase activity by providing greater access to the active site.


title: Hemocyanin

text: Much work has been devoted to preparing synthetic analogues of the active site of hemocyanin. One such model, which features a pair of copper centers bridged side-on by peroxo ligand, shows ν(O-O) at 741 cm and a UV-Vis spectrum with absorbances at 349 and 551 nm. Both of these measurements agree with the experimental observations for oxyHc. The Cu-Cu separation in the model complex is 3.56 Å, that of oxyhemocyanin is ca. 3.6 Å (deoxyHc: ca. 4.6 Å).


title: Hemocyanin

text: The hemocyanin found in the blood of the Chilean abalone, "Concholepas concholepas", has immunotherapeutic effects against bladder cancer in murine models. Mice primed with "C. concholepas" before implantation of bladder tumor (MBT-2) cells. Mice treated with "C. concholepas" hemocyanin showed antitumor effects: prolonged survival, decreased tumor growth and incidence, and lack of toxic effects and may have a potential use in future immunotherapy for superficial bladder cancer.


title: Hemocyanin

text: Keyhole limpet hemocyanin (KLH) is an immune stimulant derived from circulating glycoproteins of the marine mollusk "Megathura crenulata". KLH has been shown to be a significant treatment against the proliferations of breast cancer, pancreas cancer, and prostate cancer cells when delivered in vitro. Keyhole limpet hemocyanin inhibits growth of human Barrett's esophageal cancer through both apoptic and nonapoptic mechanisms of cell death.


title: Hemocyanin

text: A 2003 study of the effect of culture conditions of blood metabolites and hemocyanin of the white shrimp "Litopenaeus vannamei" found that the levels of hemocyanin, oxyhemocyanin in particular, are affected by the diet. The study compared oxyhemocyanin levels in the blood of white shrimp housed in an indoor pond with a commercial diet with that of white shrimp housed in an outdoor pond with a more readily available protein source (natural live food) as well. Oxyhemocyanin and blood glucose levels were higher in shrimp housed in outdoor ponds. It was also found that blood metabolite levels tended to be lower in low activity level species, such as crabs, lobsters, and the indoor shrimp when compared to the outdoor shrimp. This correlation is possibly indicative of the morphological and physiological evolution of crustaceans. The levels of these blood proteins and metabolites appear to be dependent on energetic demands and availability of those energy sources.


title: Amy Wax

text: Amy Laura Wax (born January 19, 1953) is an American lawyer, neurologist, and academic. She is the Robert Mundheim Professor of Law at the University of Pennsylvania Law School. Her work addresses issues in social welfare law and policy, as well as the relationship of the family, the workplace, and labor markets. She has often made remarks, about non-white people, described as white supremacist and racist.


title: Amy Wax

text: Wax was born and raised with her two sisters in a Jewish household in Troy, New York, where she attended public schools. Her father worked in the garment industry, and her mother was a teacher and an administrator in the government in Albany, New York.


title: Amy Wax

text: Wax attended and graduated from Yale University (B.S. in molecular biophysics and biochemistry, "summa cum laude", 1975). She then attended Somerville College, Oxford (Marshall Scholar in Physiology and Psychology, 1976).


title: Amy Wax

text: She next attended both Harvard Medical School (M.D. 1981) and Harvard Law School (first year of law school, 1981). Wax practiced medicine from 1982 to 1987, doing a residency in neurology at New York Hospital-Cornell Medical Center, and working as a consulting neurologist at a clinic in the Bronx and for a medical group in Brooklyn. She completed her legal education at Columbia Law School (J.D. 1987; Editor of the "Columbia Law Review"), working part-time to put herself through law school.


title: Amy Wax

text: Wax then clerked for Judge Abner J. Mikva of the U.S. Court of Appeals for the District of Columbia Circuit from 1987 to 1988. She was admitted to the New York State bar in 1988.


title: Amy Wax

text: Wax first worked in the Office of the Solicitor General of the United States of the United States Department of Justice from 1988 to 1994. During her tenure in the Office, she argued 15 cases before the United States Supreme Court. She taught at University of Virginia Law School from 1994 to 2000.


title: Amy Wax

text: Wax is the Robert Mundheim Professor of Law at the University of Pennsylvania Law School, having joined the law school's faculty in 2001. She received both the A. Leo Levin Award for Excellence in an Introductory Course, and the Harvey Levin Memorial Award for Teaching Excellence. In 2015, she received a Lindback Award for Distinguished Teaching, making her one of three Penn Law professors to have received the award in 20 years.


title: Amy Wax

text: Her academic focus is on social welfare law and policy, and the relationship of the family, the workplace, and labor markets. Wax authored "Race, Wrongs, and Remedies: Group Justice in the 21st Century" (2009).


title: Amy Wax

text: In an August 2017 piece in "The Philadelphia Inquirer" titled "Paying the price for breakdown of the country's bourgeois culture", she wrote with San Diego law professor Larry Alexander that since the 1950s, the decline of "bourgeois values" (such as hard work, self-discipline, marriage, and respect for authority) had contributed to social ills such as male labor force participation rates down to Great Depression-era levels, endemic opioid abuse, half of all children being born to single mothers, and many college students lacking basic skills. The authors asserted that "all cultures are not equal. Or at least they are not equal in preparing people to be productive in an advanced economy." She told "The Daily Pennsylvanian" that "everyone wants to go to countries ruled by white Europeans" because of their "superior" mores.


title: Amy Wax

text: In the same interview Wax strongly emphasized that she did not believe in the superiority of one race over another, but was describing the situation in various countries and cultures.


title: Amy Wax

text: In a September 2017 podcast interview with Professor Glenn Loury, Wax said: "Take Penn Law School, or some top 10 law school... Here's a very inconvenient fact . . . I don't think I've ever seen a Black student graduate in the top quarter of the class, and rarely, rarely in the top half ... I can think of one or two students who scored in the top half in my required first year course," and said that Penn Law has a racial diversity mandate for its law review. University of Pennsylvania Law School Dean Theodore Ruger responded, "Black students have graduated in the top of the class at Penn Law, and the Law Review does not have a diversity mandate. Rather, its editors are selected based on a competitive process."


title: Amy Wax

text: In July 2019, at the Edmund Burke Foundation's inaugural National Conservatism conference, Wax said, "Embracing . . . cultural distance nationalism, means in effect taking the position that our country will be better off with more whites and fewer non-whites."


title: Amy Wax

text: A petition in August 2017 seeking to fire Wax gathered about 4,000 signatures. That same month, 33 of her fellow Penn Law faculty members signed an open letter condemning statements Wax made in her "Philadelphia Inquirer" piece and "Daily Pennsylvanian" interview. The Penn Law chapter of the National Lawyers Guild condemned her comments. Graduate Employees Together – University of Pennsylvania, a group of unionizing graduate students, said: "We are outraged that a representative of our community upholds, and published, these hateful and regressive views." Asa Khalif, a leader of Black Lives Matter Pennsylvania, demanded that Wax be fired. Khalif said he had notified the university that if Wax were not fired within a week he would begin disrupting university classes and other activities with a series of protests.


title: Amy Wax

text: As a result of these controversies, in March 2018, Dean Ruger stripped Wax of her duties teaching curriculum courses to first-year students. He condemned her comments as "repugnant," and at a student town hall meeting he said "her presence here ... makes me angry, it makes me pissed off... she still works here ... sucks," but "the only way to get rid of a tenured professor is this process... that's gonna take months."


title: Amy Wax

text: In a March 2018 opinion piece in "The Wall Street Journal" titled "The University of Denial; Aggressive suppression of the truth is a central feature of American higher education," Wax wrote: The mindset that values openness understands that the truth can be inconvenient and uncomfortable... Hoarding and hiding information relevant to such differences... violates basic principles of fair play... Universities, like other institutions, scheme relentlessly to keep such facts from view.


title: Amy Wax

text: Right-wing political analyst Mona Charen said that the op-ed on bourgeois values "contained not a particle of racism" and that "if the Left cannot distinguish reasoned academic arguments from vile racist insinuations, it will strengthen the very extremists it fears." In a "Wall Street Journal" op-ed, political commentator Heather Mac Donald criticized the "hysterical response" to Wax's piece. University of Pennsylvania Law School Overseer Paul Levy resigned to protest what he termed Wax's "shameful treatment". Levy wrote in his letter of resignation: "Preventing Wax from teaching first-year students doesn't right academic or social wrongs. Rather, you are suppressing what is crucial to the liberal educational project: open, robust and critical debate over differing views of important social issues."


title: Amy Wax

text: "The New Criterion" wrote: "Dean Ruger may wish to consult a study published in the "Stanford Law Review" in 2004 which showed that in the most elite law schools ... only 8 percent of first-year black students were in the top half of their class." Robert VerBruggen, deputy managing editor of the "National Review", cited papers he said supported Wax's claims and wrote, "If Penn Law is different, or if things have changed in recent years, let's see some numbers."


title: Amy Wax

text: Jonathan Zimmerman, who teaches education and history at Penn, wrote: "I think a lot of what Amy Wax says is wrong. But ... I also think it's my duty to defend her right to say it, and to plead for a more honest and fair debate about it... we should want everyone to hear what she says, so that they can come to their own educated conclusions."


title: Amy Wax

text: In 2021, Wax wrote that "the United States is better off with fewer Asians," claiming Asians are ungrateful for the advantages of living in the US and vote disproportionately for the "pernicious" Democratic Party, which she called "mystifying" because the Democratic Party "demands equal outcomes despite clear . . . group differences" and "valorizes blacks." She favorably cited Enoch Powell while calling for stricter race-based immigration restrictions against Asians.


title: Amy Wax

text: In April 2022, Wax said on Tucker Carlson Today that "blacks" and other "non-western" groups harbor "resentment, shame, and envy" against western people for their "outsized achievements and contributions." Wax then attacked Indian immigrants for criticizing things in the US when "their country is a shithole" and went on to say that "the role of envy and shame in the way that the third world regards the first world [...] creates ingratitude of the most monstrous kind."


title: Amy Wax

text: Penn Law School's dean, Theodore Ruger, called Wax's statements about Asians "racist", "white supremacist", and "diametrically opposed to the policies and ethos of this institution". Glenn Loury, the Brown professor who had hosted the interview, called her comments "outrageous" and said, "What she said about the Asians could have been said, and was said, about the Jews not so long ago. Today we call that antisemitism." As of January 5 2022, nearly 9,000 law students had signed a petition to have Wax suspended. The statements drew condemnation from both local Pennsylvania papers and national press.


title: Amy Wax

text: These comments drew heavy criticism by the Indian-American community, including Penn Law faculty Neil Makhija and US lawmaker Raja Krishnamoorthi who called these comments irresponsible and said, "Such comments create hatred and fear, and cause real harm to minority communities."


title: Data structure alignment

text: Data structure alignment is the way data is arranged and accessed in computer memory. It consists of three separate but related issues: data alignment, data structure padding, and packing.


title: Data structure alignment

text: The CPU in modern computer hardware performs reads and writes to memory most efficiently when the data is "naturally aligned", which generally means that the data's memory address is a multiple of the data size. For instance, in a 32-bit architecture, the data may be aligned if the data is stored in four consecutive bytes and the first byte lies on a 4-byte boundary.


title: Data structure alignment

text: "Data alignment" is the aligning of elements according to their natural alignment. To ensure natural alignment, it may be necessary to insert some "padding" between structure elements or after the last element of a structure. For example, on a 32-bit machine, a data structure containing a 16-bit value followed by a 32-bit value could have 16 bits of "padding" between the 16-bit value and the 32-bit value to align the 32-bit value on a 32-bit boundary. Alternatively, one can "pack" the structure, omitting the padding, which may lead to slower access, but uses three quarters as much memory.


title: Data structure alignment

text: Although data structure alignment is a fundamental issue for all modern computers, many computer languages and computer language implementations handle data alignment automatically. Fortran, Ada, PL/I, Pascal, certain C and C++ implementations, D, Rust, C#, and assembly language allow at least partial control of data structure padding, which may be useful in certain special circumstances.


title: Data structure alignment

text: A memory address "a" is said to be "n-byte aligned" when "a" is a multiple of "n" (where "n" is a power of 2). In this context, a byte is the smallest unit of memory access, i.e. each memory address specifies a different byte. An "n"-byte aligned address would have a minimum of least-significant zeros when expressed in binary.


title: Data structure alignment

text: The alternate wording "b-bit aligned" designates a "b/8 byte aligned" address (ex. 64-bit aligned is 8 bytes aligned).


title: Data structure alignment

text: A memory access is said to be "aligned" when the data being accessed is "n" bytes long and the datum address is "n"-byte aligned. When a memory access is not aligned, it is said to be "misaligned". Note that by definition byte memory accesses are always aligned.


title: Data structure alignment

text: A memory pointer that refers to primitive data that is "n" bytes long is said to be "aligned" if it is only allowed to contain addresses that are "n"-byte aligned, otherwise it is said to be "unaligned". A memory pointer that refers to a data aggregate (a data structure or array) is "aligned" if (and only if) each primitive datum in the aggregate is aligned.


title: Data structure alignment

text: Note that the definitions above assume that each primitive datum is a power of two bytes long. When this is not the case (as with 80-bit floating-point on x86) the context influences the conditions where the datum is considered aligned or not.


title: Data structure alignment

text: Data structures can be stored in memory on the stack with a static size known as "bounded" or on the heap with a dynamic size known as "unbounded".


title: Data structure alignment

text: The CPU accesses memory by a single memory word at a time. As long as the memory word size is at least as large as the largest primitive data type supported by the computer, aligned accesses will always access a single memory word. This may not be true for misaligned data accesses.


title: Data structure alignment

text: If the highest and lowest bytes in a datum are not within the same memory word the computer must split the datum access into multiple memory accesses. This requires a lot of complex circuitry to generate the memory accesses and coordinate them. To handle the case where the memory words are in different memory pages the processor must either verify that both pages are present before executing the instruction or be able to handle a TLB miss or a page fault on any memory access during the instruction execution.


title: Data structure alignment

text: Some processor designs deliberately avoid introducing such complexity, and instead yield alternative behavior in the event of a misaligned memory access. For example, implementations of the ARM architecture prior to the ARMv6 ISA require mandatory aligned memory access for all multi-byte load and store instructions. Depending on which specific instruction was issued, the result of attempted misaligned access might be to round down the least significant bits of the offending address turning it into an aligned access (sometimes with additional caveats), or to throw an MMU exception (if MMU hardware is present), or to silently yield other potentially unpredictable results. The ARMv6 and later architectures support unaligned access in many circumstances, but not necessarily all.


title: Data structure alignment

text: When a single memory word is accessed the operation is atomic, i.e. the whole memory word is read or written at once and other devices must wait until the read or write operation completes before they can access it. This may not be true for unaligned accesses to multiple memory words, e.g. the first word might be read by one device, both words written by another device and then the second word read by the first device so that the value read is neither the original value nor the updated value. Although such failures are rare, they can be very difficult to identify.


title: Data structure alignment

text: Although the compiler (or interpreter) normally allocates individual data items on aligned boundaries, data structures often have members with different alignment requirements. To maintain proper alignment the translator normally inserts additional unnamed data members so that each member is properly aligned. In addition, the data structure as a whole may be padded with a final unnamed member. This allows each member of an array of structures to be properly aligned.


title: Data structure alignment

text: Padding is only inserted when a structure member is followed by a member with a larger alignment requirement or at the end of the structure. By changing the ordering of members in a structure, it is possible to change the amount of padding required to maintain alignment. For example, if members are sorted by descending alignment requirements a minimal amount of padding is required. The minimal amount of padding required is always less than the largest alignment in the structure. Computing the maximum amount of padding required is more complicated, but is always less than the sum of the alignment requirements for all members minus twice the sum of the alignment requirements for the least aligned half of the structure members.


title: Data structure alignment

text: Although C and C++ do not allow the compiler to reorder structure members to save space, other languages might. It is also possible to tell most C and C++ compilers to "pack" the members of a structure to a certain level of alignment, e.g. "pack(2)" means align data members larger than a byte to a two-byte boundary so that any padding members are at most one byte long. Likewise, in PL/I a structure may be declared codice_1 to eliminate all padding except around bit strings.


title: Data structure alignment

text: One use for such "packed" structures is to conserve memory. For example, a structure containing a single byte and a four-byte integer would require three additional bytes of padding. A large array of such structures would use 37.5% less memory if they are packed, although accessing each structure might take longer. This compromise may be considered a form of space–time tradeoff.


title: Data structure alignment

text: Although use of "packed" structures is most frequently used to conserve memory space, it may also be used to format a data structure for transmission using a standard protocol. However, in this usage, care must also be taken to ensure that the values of the struct members are stored with the endianness required by the protocol (often network byte order), which may be different from the endianness used natively by the host machine.


title: Data structure alignment

text: The following formulas provide the number of padding bytes required to align the start of a data structure (where "mod" is the modulo operator):


title: Data structure alignment

text: For example, the padding to add to offset 0x59d for a 4-byte aligned structure is 3. The structure will then start at 0x5a0, which is a multiple of 4. However, when the alignment of "offset" is already equal to that of "align", the second modulo in "(align - (offset mod align)) mod align" will return zero, therefore the original value is left unchanged.


title: Data structure alignment

text: Since the alignment is by definition a power of two, the modulo operation can be reduced to a bitwise boolean AND operation.


title: Data structure alignment

text: The following formulas produce the correct values (where "&" is a bitwise AND and "~" a bitwise NOT) -- providing the offset is unsigned or the system uses two's complement arithmetic:


title: Data structure alignment

text: Data structure members are stored sequentially in memory so that, in the structure below, the member Data1 will always precede Data2; and Data2 will always precede Data3:


title: Data structure alignment

text: If the type "short" is stored in two bytes of memory then each member of the data structure depicted above would be 2-byte aligned. Data1 would be at offset 0, Data2 at offset 2, and Data3 at offset 4. The size of this structure would be 6 bytes.


title: Data structure alignment

text: The type of each member of the structure usually has a default alignment, meaning that it will, unless otherwise requested by the programmer, be aligned on a pre-determined boundary. The following typical alignments are valid for compilers from Microsoft (Visual C++), Borland/CodeGear (C++Builder), Digital Mars (DMC), and GNU (GCC) when compiling for 32-bit x86:


title: Data structure alignment

text: The only notable differences in alignment for an LP64 64-bit system when compared to a 32-bit system are:


title: Data structure alignment

text: After compilation the data structure will be supplemented with padding bytes to ensure a proper alignment for each of its members:


title: Data structure alignment

text: The compiled size of the structure is now 12 bytes. It is important to note that the last member is padded with the number of bytes required so that the total size of the structure should be a multiple of the largest alignment of any structure member (alignment(int) in this case, which = 4 on linux-32bit/gcc).


title: Data structure alignment

text: In this case 3 bytes are added to the last member to pad the structure to the size of 12 bytes (alignment(int) × 3).


title: Data structure alignment

text: In this example the total size of the structure , not 5 (so that the size is a multiple of 4 (alignment of float)).


title: Data structure alignment

text: In this example the total size of the structure , not 5 (not 8 either) (so that the size is a multiple of 2 (alignment(short) = 2 on linux-32bit/gcc)).


title: Data structure alignment

text: It is possible to change the alignment of structures to reduce the memory they require (or to conform to an existing format) by reordering structure members or changing the compiler's alignment (or “packing”) of structure members.


title: Data structure alignment

text: The compiled size of the structure now matches the pre-compiled size of 8 bytes. Note that has been replaced (and thus eliminated) by and is no longer necessary as the structure is already aligned to the size of a long word.


title: Data structure alignment

text: The alternative method of enforcing the structure to be aligned to a one byte boundary will cause the pre-processor to discard the pre-determined alignment of the structure members and thus no padding bytes would be inserted.


title: Data structure alignment

text: While there is no standard way of defining the alignment of structure members, some compilers use directives to specify packing inside source files. Here is an example:


title: Data structure alignment

text: This structure would have a compiled size of 6 bytes on a 32-bit system. The above directives are available in compilers from Microsoft, Borland, GNU, and many others.


title: Data structure alignment

text: On some Microsoft compilers, particularly for RISC processors, there is an unexpected relationship between project default packing (the /Zp directive) and the directive. The directive can only be used to reduce the packing size of a structure from the project default packing. This leads to interoperability problems with library headers which use, for example, , if the project packing is smaller than this. For this reason, setting the project packing to any value other than the default of 8 bytes would break the directives used in library headers and result in binary incompatibilities between structures. This limitation is not present when compiling for x86.


title: Data structure alignment

text: It would be beneficial to allocate memory aligned to cache lines. If an array is partitioned for more than one thread to operate on, having the sub-array boundaries unaligned to cache lines could lead to performance degradation. Here is an example to allocate memory (double array of size 10) aligned to cache of 64 bytes.


title: Data structure alignment

text: Alignment concerns can affect areas much larger than a C structure when the purpose is the efficient mapping of that area through a hardware address translation mechanism (PCI remapping, operation of a MMU).


title: Data structure alignment

text: For instance, on a 32-bit operating system, a 4 KiB (4096 Bytes) page is not just an arbitrary 4 KiB chunk of data. Instead, it is usually a region of memory that's aligned on a 4 KiB boundary. This is because aligning a page on a page-sized boundary lets the hardware map a virtual address to a physical address by substituting the higher bits in the address, rather than doing complex arithmetic.


title: Data structure alignment

text: Example: Assume that we have a TLB mapping of virtual address 0x2CFC7000 to physical address 0x12345000. (Note that both these addresses are aligned at 4 KiB boundaries.) Accessing data located at virtual address va=0x2CFC7ABC causes a TLB resolution of 0x2CFC7 to 0x12345 to issue a physical access to pa=0x12345ABC. Here, the 20/12-bit split luckily matches the hexadecimal representation split at 5/3 digits. The hardware can implement this translation by simply combining the first 20 bits of the physical address (0x12345) and the last 12 bits of the virtual address (0xABC). This is also referred to as virtually indexed (ABC) physically tagged (12345).


title: Data structure alignment

text: This is how a dynamic allocator that has no knowledge of alignment, can be used to provide aligned buffers, at the price of a factor two in space loss.


title: Data structure alignment

text: where aligntonext("p", "r") works by adding an aligned increment, then clearing the "r" least significant bits of "p". A possible implementation is


title: St. James Infirmary Blues

text: "St. James Infirmary Blues" is an American blues song and jazz standard of uncertain origin. Louis Armstrong made the song famous in his 1928 recording on which Don Redman was credited as composer; later releases gave the name Joe Primrose, a pseudonym of Irving Mills. The melody is eight bars long, unlike songs in the classic blues genre, where there are 12 bars. It is in a minor key, and has a time signature, but has also been played in .


title: St. James Infirmary Blues

text: "St. James Infirmary Blues", sometimes known as "Gambler's Blues", is often regarded as an American folk song of anonymous origin. Moore and Baxter published a version of "Gambler's Blues" in 1925. In 1927, Carl Sandburg published a book called "The American Songbag" which contained lyrics for two versions of a song called "Those Gambler's Blues". However, the song "St. James Infirmary Blues" is sometimes credited to the songwriter Joe Primrose (a pseudonym for Irving Mills), who held copyrights for several versions of the song, registering the first in 1929. He claimed the rights to this specific title and won a case in the U.S. Supreme Court on this basis, the defendants having failed to produce the documentary evidence required by the court that the song had been known by that name for some years.


title: St. James Infirmary Blues

text: "St. James Infirmary Blues" is sometimes said to be based on an eighteenth-century traditional folk song called "The Unfortunate Rake" (also known as "The Unfortunate Lad" or "The Young Man Cut Down in His Prime") about a soldier who uses his money on prostitutes and then dies of venereal disease. But the familiar recorded versions (such as Armstrong's) bear little relation to the older traditional song. The earliest known form of this song was called "The Buck's Elegy" and is set in Covent Garden, London.


title: St. James Infirmary Blues

text: According to Robert W. Harwood, A. L. Lloyd was the first person to connect "St. James Infirmary" with "The Unfortunate Lad/Rake". Harwood refers to a five-page article by Lloyd in the January 1947 issue of the English music magazine "Keynote". In 1956, Lloyd published a revised version of this article in "Sing" magazine. In both articles Lloyd refers to an English broadside song entitled "The Unfortunate Lad", commenting that the song is sometimes known as "The Unfortunate Rake". No date or source for the latter title is given. The opening line of this version of the song refers to the "lock hospital", not to an institution named St James. The term "lock hospital" was the name of an institution in Southwark, London, where lepers were isolated and treated. The lock in Southwark was used for those suffering from venereal diseases. The longer term came into use as a generic term for a hospital treating venereal diseases. Its first recorded use is 1770.


title: St. James Infirmary Blues

text: Lloyd claims that a song collected by Cecil Sharp in the Appalachians in 1918 which contains the words "St James Hospital" is the parent song and that it looks like an elder relative of "The Dying Cowboy". The opening of that song, as quoted by Lloyd, is:


title: St. James Infirmary Blues

text: He also claims that this Appalachian version derives in turn from the version published by Such in London in the 1850s which refers to a lock hospital. The opening verse of this song, entitled "The Unfortunate Lad", is:


title: St. James Infirmary Blues

text: Lloyd's articles comment on the jazz hit "St. James Infirmary Blues". The first article asserts that "the song is, or was before it became corrupted, a narrative ballad. Such ballads are rare in Negro song...So doubts are raised about whether 'St. James Infirmary' began life as a Negro song." The second article includes the following comment on the song: "Most versions of 'Infirmary' include a number of stanzas from other songs, grafted on to the main stem – a confusion especially common with songs current among Negroes. The curious switchover from the actual death of the girl to the hypothetical death of the gambler creates some ambiguity too." Lloyd points out that in some early variants of "The Unfortunate Rake" the sex of the victim of venereal disease was female. "We realise that the confusion in the 'Infirmary', where the dead person is a woman but the funeral is ordered for a man, is surely due to the fact that the original ballad was commonly recorded in a form in which the sexes were reversed, so singers were often in two minds whether they were singing of a rakish man or a bad girl."


title: St. James Infirmary Blues

text: Lloyd's second article is cited as a reference by Kenneth Goldstein in his liner notes for a 1960 Folkways LP called "The Unfortunate Rake". These liner notes are often used as a source for the history of "St. James Infirmary Blues". One example is an article by Rob Walker. The liner notes raise the question of whether St. James' Hospital was a real place and, if so, where it was. Goldstein claimed in the notes that "St. James" refers to London's St. James Hospital, a religious foundation for the treatment of leprosy. His references list an article by Kenneth Lodewick. That article states, giving no reference or source for the idea, that the phrase "St. James Hospital" refers to a hospital of that name in London. There is some difficulty in this because the hospital in question closed in 1532 when Henry VIII acquired the land to build St James's Palace.


title: St. James Infirmary Blues

text: Another possibility suggested by Higginbotham on the basis of his claim that the song "St. James Infirmary" dates at least from the early nineteenth century, is the Infirmary section of the St James Workhouse which the St. James Parish opened in 1725 on Poland Street, Piccadilly, and which continued well into the nineteenth century. This St. James Infirmary was contemporaneous with the estimated advent of the song "The Unfortunate Lad", but it is not the London Lock Hospital. Another difficulty is that, out of the early versions of the song mentioned in the references given by Goldstein, only the one collected by Cecil Sharp in the Appalachians in 1918, and one found in Canada in the 1920s, make use of the phrase "St. James".


title: St. James Infirmary Blues

text: The liner notes link the Rake to an early fragment called "My Jewel, My Joy", stating that it was heard in Dublin. The same statement appears in the Lodewick article referenced in those notes The notes given in the source cited for this fragment, a collection of songs collected by William Forde and published by P. W. Joyce, state that the song was heard in Cork, not Dublin.


title: St. James Infirmary Blues

text: The version of the "Unfortunate Rake" on the LP of that name is sung by Lloyd, of whom it has been said that he "sometimes modified lyrics or melodies to make the songs more palatable for contemporary listeners", and its first verse is as follows:


title: St. James Infirmary Blues

text: The liner notes state that Lloyd is singing a nineteenth century broadside version, but do not specify which. The Lloyd article cited in the references given in the liner notes, refers to a version published by Such and to no other version. The title and words sung by Lloyd are not those of the Such broadside which has no reference to St. James and is not called "The Unfortunate Rake". Lloyd recorded a slightly different version in 1966, this time calling the song "St James Hospital". In 1967, his book "Folk Song in England" was published. This includes some comment on the song, claims without any supporting references or information that a Czech version pre-dates the British ones, repeats the confusion between Dublin and Cork as the place where the "My Jewel My Joy" fragment had been heard, and includes an unattributed quotation of two verses that differ from the versions sung by Lloyd.


title: St. James Infirmary Blues

text: Variations typically feature a narrator telling the story of a young man "cut down in his prime" (occasionally, a young woman "cut down in her prime") as a result of morally questionable behaviour. For example, when the song moved to America, gambling and alcohol became common causes of the youth's death.


title: St. James Infirmary Blues

text: There are numerous versions of the song throughout the English-speaking world. For example, it evolved into other American standards such as "The Streets of Laredo".


title: St. James Infirmary Blues

text: The song, "Dyin' Crapshooter's Blues", has sometimes been described as a descendant of "The Unfortunate Rake", and thus related to "St. James Infirmary Blues". This song was issued as a record four times in 1927, and attributed to pianist, arranger, and band-leader Porter Grainger. Blind Willie McTell recorded a version of the former for John Lomax in 1940 and claimed to have begun writing the song around 1929.


title: St. James Infirmary Blues

text: Gottlieb considered whether there were Jewish American influences through the use of the Ukrainian Dorian mode, but only found hints of this in a version published by Siegmeister and Downes. He also suggests that there may have been Jewish influences on the rendition by Cab Calloway. A melody very similar to the Armstrong version can be found in an instrumental composition entitled "Charleston Cabin", which was recorded by Whitey Kaufman's Original Pennsylvania Serenaders in 1924 (three years before the earliest recording of "Gambler's Blues").


title: St. James Infirmary Blues

text: As with many folk songs, there is much variation in the lyric from one version to another. These are the first two stanzas as sung by Louis Armstrong on a 1928 Odeon Records release:


title: St. James Infirmary Blues

text: Some of the versions, such as the one published as "Gambler's Blues" and attributed to Carl Moore and Phil Baxter, frame the story with an initial stanza or stanzas in which a separate narrator goes down to a saloon known as "Joe's barroom" and encounters a customer who then relates the incident about the woman in the infirmary. Later verses commonly include the speaker's request to be buried according to certain instructions, which vary according to the version. Armstrong's version includes the following as its third stanza:


title: St. James Infirmary Blues

text: The song was first recorded (as "Gambler's Blues") in 1927 by Fess Williams and his Royal Flush Orchestra with credits given to Moore and Baxter. This version mentions an infirmary but not by name. The song was popular during the jazz era, and by 1930 at least eighteen different versions had been released. The Duke Ellington Orchestra recorded the song using pseudonyms such as "The Ten Black Berries", "The Harlem Hot Chocolates", and "The Jungle Band", while Cab Calloway performed a version in the 1933 Betty Boop animated film "Snow White", providing vocals and dance moves for Koko the clown.


title: St. James Infirmary Blues

text: Country music singer and yodeller Jimmie Rodgers recorded a version in 1930 (as "Those Gambler's Blues"). In 1932 Rodgers recorded "Gambling Bar Room Blues", co-written with Shelly Lee Alley, which featured new lyrics but followed a similar melody to "St. James Infirmary Blues", with similar themes of alcohol abuse, violence and despair. Cajun string band the Dixie Ramblers recorded "Barroom Blues" in 1935, with lyrics largely matching Rodgers' "Those Gambler's Blues".


title: St. James Infirmary Blues

text: In 1961, Bobby "Blue" Bland released a version of "Saint James Infirmary" on the flip side of his No. 2 R&B hit "Don't Cry No More" and included it in his album "Two Steps from the Blues". In 1967, the French-American singer Joe Dassin recorded the song. In 1968, Don Partridge released a version on his self-named album, as did Eric Burdon and the Animals on their album "Every One of Us". Dock Boggs recorded a version of the song entitled "Old Joe's Barroom" (1965).


title: St. James Infirmary Blues

text: The song was often performed by cabaret surrealists The Mystic Knights of the Oingo Boingo in Southern California; the band's vocalist and songwriter, Danny Elfman, often cited Cab Calloway as his inspiration in his youth. The White Stripes covered the song on their self-titled debut album, and Jack White says he and fellow band member, Meg White, were introduced to the song from the Betty Boop cartoon. In 1981, Bob Dylan adapted the song when he wrote and recorded "Blind Willie McTell". The song was written for his 1983 release, "Infidels", but was not released until "The Bootleg Series, Vol. 1-3: Rare and Unreleased, 1961-1991" (Columbia, 1991).


title: St. James Infirmary Blues

text: In 2012, Trombone Shorty and Booker T. Jones performed an instrumental version as the opening number of the "Red, White, and Blues" concert at the White House.


title: Chess engine

text: In computer chess, a chess engine is a computer program that analyzes chess or chess variant positions, and generates a move or list of moves that it regards as strongest.


title: Chess engine

text: A chess engine is usually a back end with a command-line interface with no graphics or windowing. Engines are usually used with a front end, a windowed graphical user interface such as Chessbase or WinBoard that the user can interact with via a keyboard, mouse or touchscreen. This allows the user to play against multiple engines without learning a new user interface for each, and allows different engines to play against each other.


title: Chess engine

text: Many chess engines are now available for mobile phones and tablets, making them even more accessible.


title: Chess engine

text: The meaning of the term "chess engine" has evolved over time. In 1986, Linda and Tony Scherzer entered their program Bebe into the 4th World Computer Chess Championship, running it on "Chess Engine," their brand name for the chess computer hardware made, and marketed by their company Sys-10, Inc. By 1990 the developers of Deep Blue, Feng-hsiung Hsu and Murray Campbell, were writing of giving their program a 'searching engine,' apparently referring to the software rather than the hardware. In December 1991, "Computer-schach & Spiele" referred to Chessbase's recently released Fritz as a 'Schach-motor,' the German translation for 'chess engine. By early 1993, Marty Hirsch was drawing a distinction between commercial chess programs such as "Chessmaster 3000" or "Battle Chess" on the one hand, and 'chess engines' such as "ChessGenius" or his own "MChess Pro" on the other. In his characterization, commercial chess programs were low in price, had fancy graphics, but did not place high on the SSDF (Swedish Chess Computer Association) rating lists while engines were more expensive, and did have high ratings.


title: Chess engine

text: In 1994, Shay Bushinsky was working on an early version of his "Junior" program. He wanted to focus on the chess playing part rather than the graphics, and so asked Tim Mann how he could get "Junior" to communicate with "Winboard." Tim's answer formed the basis for what became known as the Chess Engine Communication Protocol or Winboard engines, originally a subset of the GNU Chess command line interface.


title: Chess engine

text: Also in 1994, Stephen J. Edwards released the Portable Game Notation (PGN) specification. It mentions PGN reading programs not needing to have a "full chess engine." It also mentions three "graphical user interfaces" (GUI): XBoard, pgnRead and Slappy the database.


title: Chess engine

text: By the mid-2000s, engines had become so strong that they were able to beat even the best human players. In 2005, Michael Adams, a world top 10 player at the time, was comprehensively beaten 5½ - ½ by Hydra, drawing only one of the six games. Except for entertainment purposes, especially using engines with limited strength, matches between humans and engines are now rare; engines are increasingly regarded as tools for analysis rather than as opponents.


title: Chess engine

text: Common Winboard engines would include "Crafty," "ProDeo" (based on "Rebel"), "Chenard," "Zarkov" and "Phalanx."


title: Chess engine

text: In 1995, Chessbase released a version of their database program including Fritz 4 as a separate engine. This was the first appearance of the Chessbase protocol. Soon after, they added the engines Junior and Shredder to their product line up, including engines in CB protocol as separate programs which could be installed in the Chessbase program or one of the other Fritz style GUI's. Fritz 1-14 were only issued as Chessbase engines, while "Hiarcs," "Nimzo," "Chess Tiger" and "Crafty" have been ported to Chessbase format even though they were UCI or Winboard engines. Recently, Chessbase has begun to include Universal Chess Interface (UCI) engines in their playing programs such as "Komodo," "Houdini," "Fritz 15–16" and "Rybka" rather than convert them to Chessbase engines.


title: Chess engine

text: In 2000, Stefan Meyer-Kahlen and Franz Huber released the Universal Chess Interface, a more detailed protocol that introduced a wider set of features. Chessbase soon after dropped support for Winboard engines, and added support for UCI to their engine GUI's and Chessbase programs. Most of the top engines are UCI these days: "Stockfish," "Komodo," "Leela Chess Zero," "Houdini," "Fritz 15-16," "Rybka," "Shredder," "Fruit," "Critter," "Ivanhoe" and "Ruffian."


title: Chess engine

text: From 1998, the German company Millenium 2000 briefly moved from dedicated chess computers into the software market, developing the Millennium Chess System (MCS) protocol for a series of CD's containing "ChessGenius" or "Shredder," but after 2001 ceased releasing new software. A more longstanding engine protocol has been used by the Dutch company, Lokasoft, which eventually took over the marketing of Ed Schröder's "Rebel."


title: Chess engine

text: Chess engines increase in playing strength continually. This is partly due to the increase in processing power that enables calculations to be made to ever greater depths in a given time. In addition, programming techniques have improved, enabling the engines to be more selective in the lines that they analyze and to acquire a better positional understanding. A chess engine often uses a vast previously computed opening "book" to increase its playing strength for the first several moves, up to possibly 20 moves or more in deeply analyzed lines.


title: Chess engine

text: Some chess engines maintain a database of chess positions, along with previously computed evaluations and best moves, in effect, a kind of "dictionary" of recurring chess positions. Since these positions are pre-computed, the engine merely plays one of the indicated moves in the database, thereby saving computing time, resulting in stronger, faster play.


title: Chess engine

text: Some chess engines use endgame tablebases to increase their playing strength during the endgame. An endgame tablebase includes all possible endgame positions with a small amount of material. Each position is conclusively determined as a win, loss, or draw for the player whose turn it is to move, and the number of moves to the end with best play by both sides. The tablebase identifies for every position the move which will win the fastest against an optimal defense, or the move that will lose the slowest against an optimal offense. Such tablebases are available for all chess endgames with seven pieces or fewer (trivial endgame positions are excluded, such as six white pieces versus a lone black king).


title: Chess engine

text: When the maneuvering in an ending to achieve an irreversible improvement takes more moves than the horizon of calculation of a chess engine, an engine is not guaranteed to find the best move without the use of an endgame tablebase, and in many cases can fall foul of the fifty-move rule as a result. Many engines use permanent brain (continuing to calculate during the opponent's turn) as a method to increase their strength.


title: Chess engine

text: Distributed computing is also used to improve the software code of chess engines. In 2013, the developers of the Stockfish chess playing program started using distributed computing to make improvements in the software code. , a total of more than 745 years of CPU time has been used to play more than 485 million chess games, with the results being used to make small and incremental improvements to the chess-playing software. In 2019, Ethereal author Andrew Grant started the distributed computing testing framework OpenBench, based upon Stockfish's testing framework, and it is now the most widely-used testing framework for chess engines.


title: Chess engine

text: By the late 1990s, the top engines had become so strong that few players stood a chance of winning a game against them. To give players more of a chance, engines began to include settings to adjust or limit their strength. In 2000, when Stefan Meyer-Kahlen and Franz Huber released the Universal Chess Interface protocol they included the parameters uci_limitstrength and uci_elo allowing engine authors to offer a variety of levels rated in accordance with Elo rating, as calibrated by one of the rating lists. Most GUIs for UCI engines allow users to set this Elo rating within the menus. Even engines that have not adopted this parameter will sometimes have an adjustable strength parameter (e.g. Stockfish 11). Engines which have a uci_elo parameter include Houdini, Fritz 15–16, Rybka, Shredder, Hiarcs, Junior, Zappa and Sjeng. GUI's such as Shredder, Chess Assistant, Convekta Aquarium, Hiarcs Chess Explorer or Martin Blume's Arena have dropdown menus for setting the engine's uci_elo parameter. The Fritz family GUI's, Chess Assistant and Aquarium also have independent means of limiting an engine's strength apparently based on an engine's ability to generate ranked lists of moves (called multipv for 'principle variation').


title: Chess engine

text: The results of computer tournaments give one view of the relative strengths of chess engines. However, tournaments do not play a statistically significant number of games for accurate strength determination. In fact, the number of games that need to be played between fairly evenly matched engines, in order to achieve significance, runs into the thousands and is, therefore, impractical within the framework of a tournament. Most tournaments also allow any types of hardware, so only engine/hardware combinations are being compared.


title: Chess engine

text: Historically, commercial programs have been the strongest engines. If an amateur engine wins a tournament or otherwise performs well (for example, Zappa in 2005), then it is quickly commercialized. Titles gained in these tournaments garner much prestige for the winning programs, and are thus used for marketing purposes. However, after the rise of volunteer distributed computing projects such as Leela Chess Zero and Stockfish and testing frameworks such as FishTest and OpenBench in the late 2010s, free and open source programs have largely displaced commercial programs as the strongest engines in tournaments.


title: Chess engine

text: Chess engine rating lists aim to provide statistically significant measures of relative engine strength. These lists play multiple games between engines. Some also standardize the opening books, the time controls, and the computer hardware the engines use, in an attempt to measure the strength differences of the engines only. These lists provide not only a ranking, but also margins of error on the given ratings.


title: Chess engine

text: The ratings on the rating lists, although calculated by using the Elo system (or similar rating methods), have no direct relation to FIDE Elo ratings or to other chess federation ratings of human players. Except for some man versus machine games which the SSDF had organized many years ago (when engines were far from today's strength), there is "no calibration" between any of these rating lists and player pools. Hence, the results which matter are the "ranks" and the "differences" between the ratings, and not the absolute values.


title: Chess engine

text: Missing from many rating lists are IPPOLIT and its derivatives. Although very strong and open source, there are allegations from commercial software interests that they were derived from a disassembled binary of Rybka. Due to the controversy, all these engines have been blacklisted from many tournaments and rating lists. Rybka in turn was accused of being based on Fruit, and in June 2011, the ICGA formally claimed Rybka was derived from Fruit and Crafty and banned Rybka from the International Computer Games Association World Computer Chess Championship, and revoked its previous victories (2007, 2008, 2009, and 2010). The ICGA received some criticism for this decision. Despite all this, Rybka is still included on many rating lists, such as CCRL and CEGT, in addition to Houdini, a derivative of the IPPOLIT derivative Robbolito, and Fire, a derivative of Houdini. In addition, Fat Fritz 2, a derivative of Stockfish, is also included on most of the rating lists.


title: Chess engine

text: Engines can be tested by measuring their performance on specific positions. Typical is the use of test suites where for each given position there is one best move to find. These positions can be geared towards positional, tactical or endgame play. The Nolot test suite, for instance, focuses on deep sacrifices. The BT2450 and BT2630 test suites measure the tactical capability of a chess engine and have been used by REBEL. There is also a general test suite called Brilliancy which was compiled mostly from "How to Reassess Your Chess Workbook". The Strategic Test Suite (STS) tests an engine's strategical strength. Another modern test suite is Nightmare II which contains 30 chess puzzles.


title: Chess engine

text: In 1999, Garry Kasparov played a chess game "Kasparov versus the World" over the Internet, hosted by the MSN Gaming Zone. Both sides used computer (chess engine) assistance. The "World Team" included the participation of over 50,000 people from more than 75 countries, deciding their moves by plurality vote. The game lasted four months, ending after Kasparov's 62nd move when he announced a forced checkmate in 28 moves found with the computer program Deep Junior. The World Team voters resigned on October 22. After the game, Kasparov said: "It is the greatest game in the history of chess. The sheer number of ideas, the complexity, and the contribution it has made to chess make it the most important game ever played."


title: Chess engine

text: Some chess engines have been developed to play chess variants, adding the necessary code to simulate non-standard chess pieces, or to analyze play on non-standard boards. ChessV and Fairy-Max, for example, are both capable of playing variants on a chessboard up to 12×8 in size, such as Capablanca Chess (10×8 board).


title: Chess engine

text: For larger boards, however, there are few chess engines that can play effectively, and indeed chess games played on an unbounded chessboard (infinite chess) are virtually untouched by chess-playing software, although theoretically a program using a MuZero-derived algorithm could handle an unbounded state space.


title: Chess engine

text: XBoard/Winboard was one of the earliest graphical user interfaces (GUI). Tim Mann created it to provide a GUI for the GNU Chess engine, but after that, other engines such as Crafty appeared which used the Winboard protocol. Eventually, the program Chessmaster included the option to import other Winboard engines in addition to the King engine which was included.


title: Chess engine

text: In 1995, Chessbase began offering the Fritz engine as a separate program within the Chessbase database program and within the Fritz GUI. Soon after, they added the Junior and Shredder engines to their product line up, packaging them within the same GUI as was used for Fritz. In the late 1990s, the Fritz GUI was able to run Winboard engines via an adapter, but after 2000, Chessbase simply added support for UCI engines, and no longer invested much effort in Winboard.


title: Chess engine

text: In 2000, Stefan Meyer-Kahlen started selling Shredder in a separate UCI GUI of his own design, allowing UCI or Winboard engines to be imported into it.


title: Chess engine

text: Convekta's Chess Assistant and Lokasoft's ChessPartner also added the ability to import Winboard and UCI engines into their products. Shane Hudson developed Shane's Chess Information Database, a free GUI for Linux, Mac and Windows. Martin Blume developed Arena, another free GUI for Linux and Windows. Lucas Monge entered the field with the free Lucas Chess GUI. All three can handle both UCI and Winboard engines.


title: Chess engine

text: On Android, Aart Bik came out with Chess for Android, another free GUI, and Gerhard Kalab's Chess PGN Master and Peter Osterlund's Droidfish can also serve as GUIs for engines.


title: Bugis

text: The Bugis people, also known as Buginese, are an ethnicity—the most numerous of the three major linguistic and ethnic groups of South Sulawesi (the others being Makassar and Toraja), in the south-western province of Sulawesi, third-largest island of Indonesia. The Bugis in 1605 converted to Islam from Animism. The main religion embraced by the Bugis is Islam, with a small minority adhering to Christianity or a pre-Islamic indigenous belief called "Tolotang".


title: Bugis

text: Despite the population numbering only around six million, the Bugis are influential in the politics in modern Indonesia, and historically influential on the Malay peninsula, Sumatra, Borneo, Lesser Sunda Islands and other parts of the archipelago where they have migrated, starting in the late seventeenth century. The third president of Indonesia, B. J. Habibie, and a former vice president of Indonesia, Jusuf Kalla, are Bugis. In Malaysia, the former prime minister Muhyiddin Yassin has Bugis ancestry.


title: Bugis

text: The Bugis people speak a distinct regional language in addition to Indonesian, called Bugis (), with several different dialects. The Bugis language belongs to the South Sulawesi language group; other members include Makassarese, Toraja, Mandar and Massenrempulu. The name Bugis is an exonym which represents an older form of the name; "(To) Ugi" is the endonym.


title: Bugis

text: The earliest inhabitant of South Sulawesi is potentially related to the Wajak Man, of the Proto-Australoid origin. There are a few flake materials found in Walanae River valley and Maros, likely dating between 40,000 and 19,000 BC. The hunter-gatherer culture in South Sulawesi is also known as Toalean culture, and largely based on blade, flake and microlith complex. They are probably of Melanesoid or Australoid stock, hence related to the contemporary population of New Guinea or Australian aborigines.


title: Bugis

text: In 2015, the remains of Bessé´, a young woman was unearthed Leang Panninge, South Sulawesi. Dated over 7,200 years old, half of her DNA was identified to be connected to the indigenous Australians, the people in New Guinea and the Western Pacific; together with a previously unknown and unique human lineage that diverged approximately 37,000 years ago. Her DNA provided important evidence pertaining to the understanding on ancient human migration.


title: Bugis

text: Their Austronesian ancestors settled on Sulawesi around 2500 B.C. There is "historical linguistic evidence of some late Holocene immigration of Austronesian speakers to South Sulawesi from Taiwan"—which means that the Bugis have "possible ultimate ancestry in South China", and that as a result of this immigration, "there was an infusion of an exogenous population from China or Taiwan." Migration from South China by some of the paternal ancestors of the Bugis is also supported by studies of Human Y-chromosome DNA haplogroups.


title: Bugis

text: The homeland of the Bugis is the area around Lake Tempe and Lake Sidenreng in the Walannae Depression in the south-west peninsula of Sulawesi. It was here that the ancestors of the present-day Bugis settled, probably in the mid- to late second millennium B.C. The area is rich in fish and wildlife and the annual fluctuation of Lake Tempe (a reservoir lake for the Bila and Walannae rivers) allows speculative planting of wet rice, while the hills can be farmed by swidden or shifting cultivation, wet rice, hunting and gathering. Around A.D. 1200, the availability of prestigious imported goods including Chinese and South-East Asian ceramics and Gujerati print-block textiles, coupled with newly discovered sources of iron ore in Luwu stimulated an agrarian revolution which expanded from the great lakes region into the lowland plains to the east, south and west of the Walennae depression. This led over the next four hundred years to the development of the major kingdoms of South Sulawesi, and the social transformation of chiefly societies into hierarchical proto-states.