title: General officers in the United States

text: A year prior to his death, Washington was appointed by President John Adams to the rank of lieutenant general in the United States Army during the Quasi-War with France. Washington never exercised active authority under his new rank, however, and Adams made the appointment to frighten the French, with whom war seemed certain.


title: General officers in the United States

text: In an act of Congress on March 3, 1799, Congress provided "that a Commander of the United States shall be appointed and commissioned by the style of General of the Armies of the United States and the present office and title of Lieutenant General shall thereafter be abolished." The proposed senior general officer rank was not bestowed, however. When George Washington died, he was listed as a lieutenant general on the rolls of the United States Army.


title: General officers in the United States

text: After the Revolutionary War, the tiny United States Army at first had no active duty General Officers. When General Officers were appointed again, the highest rank in the Army was Major General, with the senior Major General on the Army rolls known as the Commanding General of the United States Army. The position was abolished at the start of the 20th century and replaced by that of Chief of Staff of the United States Army.


title: General officers in the United States

text: The rank of lieutenant general remained inactive from the end of the Revolutionary War until the mid-19th century. During the Mexican–American War, President Polk asked Congress to authorize the creation of a lieutenant-general. However, it soon became clear that Polk intended to give this rank to Senator Thomas Hart Benton and place him in charge of the entire war effort—a move that would place Benton, a Democrat and Polk ally, above the two Whig generals who had been conducting the war (Zachary Taylor and Winfield Scott). As a result, Congress refused to authorize this rank.


title: General officers in the United States

text: The rank of lieutenant general was finally created in 1855, when Winfield Scott received a brevet promotion to this rank.


title: General officers in the United States

text: On March 13, 1861, General Order No. 6 said that the position of "Major General Commanding the Army" was entitled to wear three stars. In 1864, Ulysses S. Grant was appointed lieutenant general and took command of the Union forces. He used the three-star insignia formerly assigned to the position of Major General Commanding the Army.


title: General officers in the United States

text: The Confederate States Army used the rank of lieutenant general for its corps commanders prior to the U.S. Army's adoption of the term. The two ranks were not synonymous. Unlike the Union Army, the Confederate States Army promoted numerous officers to the ranks of Lieutenant General and General (18 and 7, respectively).


title: General officers in the United States

text: In the 19th century, the rank of a U.S. general was also shown by the arrangement of buttons on the coat. This was a feature of the general dress uniform until the Army abandoned blue uniforms during World War I.


title: General officers in the United States

text: On July 25, 1866, the U.S. Congress established the rank of "General of the Army of the United States" for Ulysses S. Grant. When appointed General of the Army, Grant wore the rank insignia of four stars and coat buttons arranged in three groups of four.


title: General officers in the United States

text: Unlike the 1944 rank with a similar title, the 1866 rank of General of the Army was a four-star rank, and as opposed to the current pool of four-star generals, only one officer could hold the 1866–1888 rank of General of the Army at any time.


title: General officers in the United States

text: After Grant retired to become President of the United States, he was succeeded as General of the Army by William T. Sherman, effective March 4, 1869. In 1872, Sherman ordered the insignia changed to two stars with the arms of the United States in between. Sherman wore this insignia during his term as General of the Army of the United States. When Sheridan succeeded him, he re-adopted the four-star insignia which Grant used to wear.


title: General officers in the United States

text: By an Act of June 1, 1888, the grade of lieutenant general was discontinued and merged with that of General of the Army, which was then conferred upon Philip H. Sheridan. (The cover of Sheridan's autobiography was decorated with four stars within a rectangle evocative of the four-star shoulder strap worn by Grant.) The rank of General of the Army ceased to exist upon the death of Sheridan on August 5, 1888, and the highest rank of the United States Army was again the two-star major general rank. Over the next three decades, statute allowed one senior officer to be promoted to Lieutenant General, typically the Commanding General or the Chief of Staff.


title: General officers in the United States

text: Three-star Lieutenant Generals and four-star Generals were reauthorized temporarily for World War I. Tasker H. Bliss (December 31, 1853 – November 9, 1930) and John J. Pershing (13 September 1860–15 July 1948) were promoted to General in October 1917. Peyton C. March was promoted to General in May 1918. Hunter Liggett and Robert Lee Bullard were promoted to Lieutenant General on October 16, 1918. On September 3, 1919, granted Pershing the rank of "General of the Armies of the United States" in recognition of his performance as the commander of the American Expeditionary Force. Pershing was authorized to create his insignia for the new rank and chose to wear four gold stars for the rest of his career, which distinguished his insignia from the four (temporary) silver stars worn by Army Chiefs of Staff of the 1910s and early 1920s. After the war, in 1920, the Lieutenant Generals and Generals reverted to their permanent ranks of Major General, except for Pershing. Pershing retired from the United States Army on September 13, 1924, and retained his rank of General of the Armies of the United States until his death in 1948. He was later considered a five or six-star general as the result of the creation of the General of the Army rank in 1944. The rank of general was reauthorized in 1929 as a unique temporary rank of the Army Chief of Staff starting with Charles Pelot Summerall. The main purpose of this was to give the Chief of Staff of the Army, who had been a major general, equal rank with the Chief of Naval Operations, a four-star position since 1916.


title: General officers in the United States

text: Lieutenant Generals were reauthorized on August 5, 1939. Four Lieutenant Generals were authorized as temporary ranks for the commanding generals of the four numbered field armies at the time. Subsequently, the commanding generals of the Panama Canal and Hawaiian departments were raised to lieutenant general as well. The four-star rank of General remained unique to the Chief of Staff, as authorized by the act of February 23, 1929.


title: General officers in the United States

text: During World War II most American Generals held temporary or "theater" appointments in the Army of the United States.


title: General officers in the United States

text: Until the Second World War, the highest Marine Corps general rank was that of Major General, with Thomas Holcomb becoming the first three-star Marine general and Alexander Vandegrift becoming the first four-star Marine general (both on active duty) in history. Vandegrift's rank was awarded after becoming the Commandant of the Marine Corps.


title: General officers in the United States

text: The second version of General of the Army, colloquially known as a "Five-star General" was created by Pub.L. passed on December 14, 1944, first as a temporary rank, then made permanent March 23, 1946, by an act of the 79th Congress. It was created to give the most senior American commanders parity of rank with their British counterparts holding the rank of field marshal. The acts also created a comparable rank of Fleet Admiral for the Navy. This second General of the Army rank is not considered comparable to the American Civil War era version.


title: General officers in the United States

text: The insignia for General of the Army, as created in 1944, consisted of five stars in a pentagonal pattern, with points touching. The five officers who have held the 1944 version of General of the Army were:


title: General officers in the United States

text: The timing of the first four appointments was coordinated with the appointment of the U.S. Navy's five-star Fleet Admirals (on 15, 17, and December 19, 1944) to establish both a clear order of seniority and a near-equivalence between the services.


title: General officers in the United States

text: A historical rumor suggests that the title 'General of the Army' was used instead of the 'Field Marshal' so that George Marshall would not be known as "Marshal Marshall". Most military sources agree that it is more likely that the rank was named after its 19th-century counterpart and was so named because the rank of Field Marshal was considered by the U.S. military to be a European rank.


title: General officers in the United States

text: Dwight Eisenhower resigned his Army commission on May 31, 1952, to run for president. After he served two terms, his successor, John F. Kennedy, signed on March 23, 1961, which returned Eisenhower to Active Duty of Regular Army, to the grade of General of the Army grandfathered to December 1944.


title: General officers in the United States

text: This rank is today commemorated on the signs denoting Interstate Highways as part of the Eisenhower Interstate System, which display five silver stars on a light blue background.


title: General officers in the United States

text: Official abbreviations below are used in the U.S. Army only. The U.S. Air Force does not abbreviate general officer ranks in signature blocks, but "Brigadier General," "Major General," and "Lieutenant General" (without abbreviating periods) are commonly used.


title: General officers in the United States

text: After the close of the Second World War, Generals were normally promoted permanently to Brigadier General and Major General, with temporary promotions to Lieutenant General and General to fill senior positions as needed. In theory, a General would be expected to vacate their three- or four-star rank at the termination of their assignment, unless they were placed in an equal or higher-ranking billet. Douglas MacArthur, who served as four-star general and Army Chief of Staff, reverted to two stars after his CoS tour ended but chose to stay on active duty in the United States Army.


title: General officers in the United States

text: The practice of using Lieutenant General and General as a temporary rank continues to the current day, although the term "temporary" is in name only since most three- and four-star generals are expected to retain their rank regardless of their assignment. Such officers are also almost always granted permanent retirement rank, as well, in the last grade they held.


title: General officers in the United States

text: There have been no officers appointed to the rank of General of the Army since Omar Bradley and, in the 21st century U.S. military, further appointments are highly unlikely unless the United States were to become involved in a major war on the scale of World War II.


title: General officers in the United States

text: In the 1990s, the Defense Department gave some indication that the Chairman of the Joint Chiefs of Staff would possibly one day be a position worthy of the rank General of the Army, Fleet Admiral, or General of the Air Force as appropriate. This would be problematic in that with the appointment of United States Marine Corps generals as chairman, there is no current five-star USMC rank. Congressional sources indicated that there were no plans to promote any modern-day general officers to the rank of General of the Army.


title: General officers in the United States

text: The rank of General of the Army is still maintained as a rank of the U.S. military, and could again be bestowed pending approval of the United States Congress. The rank would carry a special pay grade just as the current ranks of officers do. Currently, U.S. military policy is that General of the Army, General of the Air Force, and Fleet Admiral are rankings only to be used in time of war when the commanding officer must be equal to or of higher rank than those commanding armies from another nation.


title: General officers in the United States

text: After World War II, which saw the introduction of U.S. "five-star" officers who outranked Washington, both Congress and the President revisited the issue of Washington's rank. To maintain George Washington's proper position as the first Commanding General of the United States Army, he was appointed, posthumously, to the grade of General of the Armies of the United States by congressional joint resolution January 19, 1976, approved by President Gerald R. Ford on October 11, 1976. The Department of the Army , issued on March 13, 1978, by Secretary of the Army Clifford Alexander, Jr., had an effective appointment date of July 4, 1976.


title: This Is How We Do It

text: "This Is How We Do It" is the debut single by American singer Montell Jordan. It was released by Def Jam Recordings on February 6, 1995 as the lead single from his debut album, also titled "This Is How We Do It" (1995). The single was Def Jam's first R&B release.


title: This Is How We Do It

text: The song is representative of the hip hop soul style popular at the time. The song features Jordan singing over an enhanced Teddy Riley drumbeat sample of Slick Rick's "Children's Story" which in turn has an added interpolation of the bass of Bob James' "Nautilus". "This Is How We Do It" peaked at number one on the "Billboard" Hot 100 on April 15, 1995, rising from number six the previous week and displacing Madonna's "Take a Bow" from the top spot. It remained at number one for seven consecutive weeks. It was also number one for seven weeks on the R&B singles chart. The single sold one million copies domestically and earned a platinum certification from the RIAA.


title: This Is How We Do It

text: The song earned Jordan a Grammy Award nomination for Best Male R&B Vocal Performance at the 38th Annual Grammy Awards. The same year, the song was named Best R&B 12-inch at the International Dance Music Awards in Miami.


title: This Is How We Do It

text: Ralph Tee from British magazine "Music Week"'s "RM" Dance Update wrote, "This record is typical of everything that urban contemporary soul is about with its chugging swing/funk rhythms and intense Aaron Hall-style vocal and it's been flying out on import lately. Its main appeal is the infectious multi-vocal chorus, blasting out the song's title to ram home its anthemic qualities." He added that "there's masses of dancefloor appeal". Another editor, James Hamilton described "This Is How We Do It" as a "soulfully whined, chanted and rapped rolling jackswing joller".


title: This Is How We Do It

text: In 2002, British girl group Mis-Teeq released their version as a double A-side with "Roll On", titled "Roll On / This Is How We Do It". It peaked at number 7 on the UK charts, faring four places better than the original. The original by Jordan was featured in the 2002 film "Ali G Indahouse", along with the Rishi Rich mix of Mis-Teeq's version, which is also on the film's soundtrack. "This Is How We Do It" is included on the Special Edition of the album "Lickin' on Both Sides".


title: This Is How We Do It

text: Dutch DJ Joe Stone released a remixed version of the song in 2015 with Jordan credited as the featured artist.


title: Wealth and religion

text: The correlation between wealth and religion has been subject to academic research. Wealth is the status of being the beneficiary or proprietor of a large accumulation of capital and economic power. Religion is a cultural system that often involves belief in supernatural forces and may intend to provide a moral system or a meaning of life. Jews typically rank as the highest income groups in the United States, with Hindus and Episcopalians behind them.


title: Wealth and religion

text: According to a study from 2015, Christians hold the largest amount of wealth (55% of the total world wealth), followed by Muslims (5.8%), Hindus (3.3%), and Jews (1.1%). According to the same study it was found that adherents under the classification "Irreligion", or other religions, hold about 34.8% of the total global wealth.


title: Wealth and religion

text: A study done by the nonpartisan wealth research firm New World Wealth found that 56.2% of the 13.1 million millionaires in the world were Christians, while 6.5% were Muslims, 3.9% were Hindu, and 1.7% were Jewish; 31.7% were identified as adherents of "other" religions or "not religious".


title: Wealth and religion

text: A study in the United States (based on data from 1985 to 1998), conducted by the sociologist Lisa A. Keister and published in the "Social Forces" journal, found that adherents of Judaism and Episcopalianism accumulated the most wealth, believers in Catholicism and mainline Protestants were in the middle, while conservative Protestants accumulated the least; in general, people who attend religious services accumulated more wealth than those who do not (taking into account variations of education and other factors). Keister suggested that wealth accumulation is shaped by family processes. According to the study, the median net worth of people believing in Judaism is calculated at 150,890 USD, while the median net worth of conservative Protestants (including Baptists, Jehovah's Witnesses, Seventh-day Adventists, Christian Scientists) was US$26,200. The overall median in the dataset was US$48,200.


title: Wealth and religion

text: Another study in the United States, from 2012, stated that 48% of Hindus had a household income of $100,000 or more, and 70% make at least $75,000, which is the highest among all religions in United States.


title: Wealth and religion

text: According to a 2014 study by the Pew Research Center, Jewish again ranked as the most financially successful religious group in the United States, with 44% of Jews living in households with incomes of at least $100,000, followed by Hindu (36%), Episcopalians (35%), and Presbyterians (32%). Amongst Jews, in 2016, Modern Orthodox Jews had a median household income of $158,000, while Open Orthodoxy Jews had a median household income of $185,000 (compared to the American median household income of $59,000 in 2016). According to the same study there is correlation between education and income, about 77% of American Hindus have an undergraduate degree and according to a study in 2020, they are earning highest with $137,000, followed by Jews (59%), Episcopalians (56%), and Presbyterians (47%).


title: Wealth and religion

text: A study published in the "American Journal of Sociology" by Lisa Keister, found that "wealth affects religion indirectly through educational attainment, fertility, and female labor force participation" but also found some evidence of direct effects of religion on wealth attainment. Keister notes that certain religious beliefs ("one should have many children", "women should not work") lower wealth accumulation, both on the micro- and macro-scale.


title: Trailer park

text: A trailer park,caravan park, mobile home park, mobile home community or manufactured home community is a temporary or permanent area for mobile homes and travel trailers. Advantages include low cost compared to other housing, and quick and easy moving to a new area (for example, when taking a job in a distant place while keeping the same home).


title: Trailer park

text: Trailer parks, especially in American culture, are stereotypically viewed as lower income housing for occupants living at or below the poverty line who have low social status. Despite the advances in trailer home technology, the trailer park image survives as evoked by a statement from Presidential adviser James Carville who, in the course of one of the Bill Clinton White House political scandals, suggested "Drag $100 bills through trailer parks, there's no telling what you'll find," in reference to Paula Jones.


title: Trailer park

text: Tornadoes and hurricanes often inflict serious damage on trailer parks, usually because the structures are not secured to the ground and their construction is significantly less able to withstand high wind forces than regular houses. However, most modern manufactured homes are built to withstand high winds, using hurricane straps and proper foundations.


title: Trailer park

text: The negative perception of trailer parks was not improved by the creation of emergency trailer parks by the Federal Emergency Management Agency (FEMA) for the displaced victims of Hurricane Katrina, the quality and temporary nature of which was disputed.


title: Trailer park

text: Many stereotypes have been developed regarding people who live in trailer parks, which are similar to stereotypes of the poor and the term "trailer trash" is often used as an adjective in the same vein as the derogatory American terms "white trash" or "ghetto". Though trailer parks appear throughout the United States, they are often associated with the Deep South and rural areas. Trailer parks became viewed as a valuable asset in the late 2010s. During that decade, REITs, private equity funds, and middle-class people looking to escape the corporate world bought them up from small mom-and-pop owners.


title: Trailer park

text: More recently referred to in the U.S. as "mobile home parks" or "manufactured housing communities", the stereotypes are often just that. Retirement communities exist in many locales that permit mobile home parks as "55+ parks" in keeping with the Housing for Older Persons Act (HOPA). Generally, at least one homeowner in these communities must be age 55 or over, and those under age 18 are rarely permitted to live there. These can be gated communities with amenities, such as swimming pools, clubhouses and onsite maintenance. Homes are often permanently installed on foundations, however, in certain circumstances, residents may not own the land their homes occupy.


title: Trailer park

text: Mobile home parks in the U.S. have become an attractive investment for financial firms such as Carlyle Group, Apollo Global Management and TPG Capital. Over 100,000 US mobile home sites were estimated to be owned by large firms in 2019. One firm, Stockbridge Capital Group, owner of about 200 mobile-home parks throughout the US "saw a return on investment of more than 30 percent between late 2016 and the end of 2017." The company's expansion into this market was facilitated by $1.3 billion in financing from Fannie Mae, which has called mobile homes "inherently affordable." Profitability for the firms owning the parks has in some cases been tied to rent increases, and has not necessarily translated into good maintenance of the mobile homes. Efforts are being mounted to allow trailer park residents a chance to buy their own trailer park and thus own the land they live on; for instance, in Colorado, trailer park owners must give residents 90 days' notice before selling.


title: Trailer park

text: In Britain and Ireland, the term halting site is used in place of trailer parks. The biggest difference in Europe is the presence of unauthorised halting sites (or trailer parks). This stems from the practice of traditionally itinerant ethnic groups, such as the Romani and Irish Travellers, to periodically during the year set up a transient community. From the late 1970s onward there was also a growth in New Age travelers culture; these groups espoused alternative lifestyles combined with a Do-It-Yourself punk ethic. The latter were a commonplace phenomenon in Germany, giving rise to expressions such as "Wagenburg", "Wagendorf", and "Bauwagenplatz" ("wagon fort", "trailer village" and "construction trailer site" respectively).


title: Trailer park

text: Either rejected from or refusing to seek entrance in municipally authorised halting sites, groups of families practising a nomadic lifestyle would establish themselves under the cover of darkness on idle land near urban centers. These unauthorised encampments were often resented by local people, perpetuating a cycle of violence, fear and discrimination. The use of land without the necessary permission also carried the threat of imprisonment for the squatting families, further worsening the socio-economic disadvantage experienced by these minorities.


title: Trailer park

text: In Germany, the Netherlands and some other European countries, local law allows for normal camping at RV parks for a short time and seasonal camping for holiday makers, and also long-time camping (for years) with hardly movable travel trailers. Sometimes these inhabitants also cultivate a garden. Some cities allow a long-time camping lot to be the regular address registered with the authorities; others do not. Many of mobile home plots are offered by RV parks that allow for all sorts of camping and offer extra plots for mobile homes (static caravans).The cost for such a plot tends to be between 400 € and 1.500 € a year, depending on the location and facilities.


title: Trailer park

text: In France, living in a trailer or mobile home for more than three months is prohibited by law, even if the resident owns the land; however, building requirements and permissions for self building of recreational solid (static) country cottages are more relaxed in France if one stays within a certain amount of square meters.


title: Trailer park

text: In the United Kingdom, "trailers" are commonly known as static caravans, and are generally used for one of two purposes: firstly as holiday homes, designed for short-term living; and secondly as retirement homes for the elderly, designed for long-term occupancy. Both types of trailers usually enjoy good amenities and are surrounded by highly manicured gardens.


title: Trailer park

text: In Australia, there is generally no differentiation between a trailer park and an RV park. The term "caravan park" is used to refer to both.


title: Lamiales

text: The order Lamiales (also known as the mint order) are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided into about 25 families. These families include Acanthaceae, Bignoniaceae, Byblidaceae, Calceolariaceae,Carlemanniaceae, Gesneriaceae, Lamiaceae, Lentibulariaceae, Linderniaceae, Martyniaceae, Mazaceae, Oleaceae, Orobanchaceae, Paulowniaceae, Pedaliaceae, Peltantheraceae, Phrymaceae, Plantaginaceae, Plocospermataceae, Schlegeliaceae, Scrophulariaceae, Stilbaceae, Tetrachondraceae, Thomandersiaceae, Verbenaceae.


title: Lamiales

text: Being one of the largest orders of flowering plants, Lamiales have representatives found all over the world. Well-known or economically important members of this order include lavender, lilac, olive, jasmine, the ash tree, teak, snapdragon, sesame, psyllium, garden sage, and a number of table herbs such as mint, basil, and rosemary.


title: Lamiales

text: Plant species within the order Lamiales are eudicots and are herbaceous or have woody stems. Zygomorphic flowers are common in Lamiales, having five petals with an upper lip of two petals and lower lip of three petals, however actinomorphic flowers are also seen.  Plant species within the order Lamiales potentially have five stamens, but these are typically reduced to two or four. Lamiales also produce a single style attached to an ovary typically containing two carpels. The ovary in the Lamiales order is mostly observed to be superior.  Lamiales inflorescence is typically seen as cyme, raceme or spike.  Fruit type in Lamiales order is usually dehiscent capsules.  Glandular hairs are present in Lamiales.


title: Lamiales

text: The Lamiales order can be found in almost all kinds of habitats world-wide. These habitats include forests, valleys, grasslands, rocky terrain, rainforests, the tropics, temperate regions, marshes, coastlines, and even frozen areas.


title: Lamiales

text: A number of species of carnivorous plants are found in the Lamiales, in the families Lentibulariaceae and Byblidaceae. Protocarnivorous plant species have also been found in the order Lamiales, specifically in the families Martyniaceae.


title: Lamiales

text: Parasitic plant species are found in the order Lamiales, belonging to the family Orobanchaceae. These parasitic plants can either be hemi-parasites or holoparasites.


title: Lamiales

text: The order Lamiales has a variety of species with anthropogenic uses, the most popular belonging to the Lamiaceae and Acanthaceae families. Many of these species in the order Lamiales produce medicinal properties from alkaloids and saponins to help a variety of infections and diseases. These alkaloids and saponins may help with digestion, the common cold or flu, asthma, liver infections, pulmonary infections and contain antioxidant properties.


title: Lamiales

text: Plant species within the order Lamiales are also known to have properties to repel insects and help control harmful diseases from insects, such as Malaria from mosquitos. The plant family Acanthaceae within the Lamiales order have bioactive secondary metabolites within their mature leaves, which have been found to be toxic to insect larvae. Botanical derived insecticides are a good alternate for chemical or synthetic insecticides as it is inexpensive, abundant and safe for other plants, non-target organisms and the environment.


title: Lamiales

text: Many species within the order Lamiales are also used as decorations, flavouring agents, cosmetics and fragrances. Natural dyes can also be extracted from plant species within Lamiales. For example, in Sardinia culture, the most common Lamiales plant species used for natural dyes is "Lavandula stoechas," where a light-green dye is extracted from the stem


title: Lamiales

text: The Lamiales previously had a restricted circumscription (e.g., by Arthur Cronquist) that included the major families Lamiaceae (Labiatae), Verbenaceae, and Boraginaceae, plus a few smaller families. In the classification system of Dahlgren the Lamiales were in the superorder Lamiiflorae (also called Lamianae). Recent phylogenetic work has shown the Lamiales are polyphyletic with respect to order Scrophulariales and the two groups are now usually combined in a single order that also includes the former orders Hippuridales and Plantaginales. Lamiales has become the preferred name for this much larger combined group. The placement of the Boraginaceae is unclear, but phylogenetic work shows this family does not belong in Lamiales.


title: Lamiales

text: Also, the circumscription of family Scrophulariaceae, formerly a paraphyletic group defined primarily by plesiomorphic characters and from within which numerous other families of the Lamiales were derived, has been radically altered to create a number of smaller, better-defined, and putatively monophyletic families.


title: Lamiales

text: Much research has been conducted in recent years regarding the dating the Lamiales lineage, although there still remains some ambiguity. A 2004 study, on the molecular phylogenetic dating of asterid flowering plants, estimated 106 million years (MY) for the stem lineage of Lamiales. A 2009 study on angiosperm diversification through time, concluded an inferred age of lower Eocene, ca. 50 MY, for Lamiales.


title: Poldek Pfefferberg

text: Leopold "Poldek" Pfefferberg (March 20, 1913 – March 9, 2001), also known as Leopold Page, was a Polish-American Holocaust survivor who inspired the Australian writer Thomas Keneally to write the Booker prize-winning novel "Schindler's Ark", which in turn was the basis for Steven Spielberg's critically acclaimed 1993 film "Schindler's List".


title: Poldek Pfefferberg

text: Pfefferberg was born into a Jewish family in Kraków, then a part of the Austria-Hungary. He gained a master's degree in philosophy and physical education from the Jagiellonian University. Pfefferberg was a high-school teacher in Kraków until 1939 and the physical education professor at Kościuszko Gymnasium in Podgórze.


title: Poldek Pfefferberg

text: After the Germans invaded Poland in 1939, he joined the Polish Army as an officer and took part in the defence of Poland against the invasion. He later explained to the Australian novelist Thomas Keneally how he was wounded on the San River where his life was saved by his sergeant major, who carried him to a field hospital. After Poland was defeated and partitioned between Nazi Germany and the Soviet Union, Pfefferberg needed to decide whether it would be safer to travel east towards the Soviets or west towards the Germans. He later recalled this choice:


title: Poldek Pfefferberg

text: We officers had to decide to go east or west. I decided not to go east, even though I was Jewish. If I had, I would have been shot with all the other poor sons of bitches in Katyn Forest.


title: Poldek Pfefferberg

text: After sneaking back to Kraków, he was imprisoned along with the rest of the area's Jews, in the Kraków Ghetto. Pfefferberg used a German-issued document to visit his soldiers in a military hospital, and also to visit his mother. This is how he first met Oskar Schindler, a Sudeten-German businessman who was taking over an enamelware factory that had been confiscated from Jews. Schindler employed Pfefferberg's mother, an interior designer, to decorate his new apartment. He later began helping Schindler trade on Kraków's wartime black market.


title: Poldek Pfefferberg

text: In 1941, he married Ludmila "Mila" Lewison, with whom he later had two children. Mila, like Pfefferberg, would become a survivor of the Kraków-Płaszów concentration camp and a "Schindlerjude."


title: Poldek Pfefferberg

text: Through this connection to Schindler, Pfefferberg was employed in Schindler's factory near the Kraków-Płaszów concentration camp outside Kraków. This enabled him to survive the extermination of 3 million Polish Jews, during which his parents, sister, brother-in-law and many other relatives were murdered. Pfefferberg described Schindler as "a modern Noah," who was able to save a number of Kraków Jews from deportation to the nearby extermination camp at Auschwitz. Those he saved became known as "Schindlerjuden" or "Schindler's Jews".


title: Poldek Pfefferberg

text: He and his wife were moved with Schindler and many others to a camp at Brünnlitz due to their presence on the famous "Schindler's list". During that time, he acquired skill as a welder. The Jews at Brünnlitz were liberated on May 9, 1945, by the Red Army.


title: Poldek Pfefferberg

text: After the war, the Pfefferbergs first settled in Budapest, then in Munich where he organized a school for refugee children. In 1948, he emigrated to the United States, where he intermittently went by the name Leopold Page. He and his wife settled in Los Angeles in 1950, eventually opening a leather goods business in Beverly Hills. In the United States he used the name Leopold Page, although in later years he apparently reverted to Pfefferberg. He tried on a number of occasions to interest the screenwriters and film-makers he met through his business in a film based on the story of Schindler and his actions in saving Polish Jews from the Nazis, arranging several interviews with Schindler for American television. Schindler's death in 1974 seemed to end any possibility of a film.


title: Poldek Pfefferberg

text: In 1980, when Thomas Keneally went into Pfefferberg's shop to ask about the price of briefcases, Pfefferberg learned that Keneally was a novelist and showed him his extensive files on Schindler. Keneally was interested, and Pfefferberg became an advisor for the book, accompanying Keneally to Poland where they visited Kraków and the sites associated with the Schindler story. Keneally dedicated "Schindler's Ark" to Pfefferberg: "who by zeal and persistence caused this book to be written."


title: Poldek Pfefferberg

text: After the publication of "Schindler's Ark" in 1982, Pfefferberg worked to persuade Steven Spielberg to film Keneally's book, using his acquaintance with Spielberg's mother to gain access. Pfefferberg claimed to have called Spielberg's office every week for 11 years. When in 1992 Spielberg agreed to make the film, Pfefferberg worked as an advisor, again making the trip to Poland to show Spielberg the sites; he appears in the film's epilogue and is listed in the end credits as a consultant, under the name Leopold Page. Pfefferberg and his wife were Spielberg's guests on the night "Schindler's List" won seven Academy Awards. In his acceptance speech for best director that night, Spielberg thanked "a survivor named Poldek Pfefferberg ... I owe him such a debt. He has carried the story of Oskar Schindler to all of us."


title: Poldek Pfefferberg

text: Pfefferberg was a founder of the Oskar Schindler Humanities Foundation, which recognises acts by individuals and organizations, regardless of race or nationality. He remarked on the Foundation:


title: Poldek Pfefferberg

text: Only when the foundation is a reality will I say I have fulfilled my obligation. Because when I am no longer here, when the Schindler Jews are not here, the foundation will still go on.


title: Excision (film)

text: Excision is a 2012 American horror film written and directed by Richard Bates, Jr., and starring AnnaLynne McCord, Traci Lords, Ariel Winter, Roger Bart, Jeremy Sumpter, Malcolm McDowell, Matthew Gray Gubler, Marlee Matlin, Ray Wise, and John Waters. The film is a feature-length adaptation of the 2008 short film of the same name. "Excision" premiered at the 2012 Sundance Film Festival. "Excision" played in the category of Park City at Midnight.


title: Excision (film)

text: Pauline is a disturbed and delusional high school student with aspirations of a career as a surgeon. Her family is dysfunctional; her younger sister Grace suffers from cystic fibrosis, and her controlling, strongly Christian mother Phyllis shares a strained marriage with Pauline’s father, Bob. Pauline has vivid dreams about herself and others being mutilated with excessive amounts of blood, after which she wakes panting in an orgasmic state.


title: Excision (film)

text: Pauline decides to lose her virginity to a boy named Adam, and wants to do so while on her period due to her fascination with blood. She and Adam have sex, and as she has an orgasm, she imagines herself choking Adam and the bed filling with blood. She then asks Adam to perform oral sex on her. Unaware that she is menstruating, he obliges, only to run to the bathroom in disgust when he sees the blood.


title: Excision (film)

text: During sex education class, Pauline takes a sample of her blood and puts it under a microscope to check for STDs. Later, she sees Adam with his girlfriend Natalie and alludes to their encounter, leading to Natalie breaking up with him. Later, Natalie and her friend throw toilet paper on Pauline's house and spray paint profanities on it. At school the next day, Pauline physically assaults both Adam and Natalie, resulting in her being expelled.


title: Excision (film)

text: Pauline overhears her parents talking and learns that Grace's doctor plans to put her on a waiting list to receive a lung transplant. That night, Grace suffers a severe coughing fit. In the morning, Pauline drugs her father with tea and ties him up before confronting an across the street neighbor who had rebuffed Pauline’s earlier attempts at friendship. She lures the girl to her backyard before using chemicals to knock her out, and subsequently drugs Grace.


title: Excision (film)

text: Pauline cuts and shaves her own hair before commencing her surgery in the garage. She transplants the healthy girl's lungs into Grace’s body and places Grace’s infected lungs on ice before stitching both girls up. Phyllis arrives home and panics at the sight of her husband bound and gagged, frantically screaming and searching the house for Grace. She finds Pauline with the bodies. Pauline explains that it is her first surgery, and urges her mother to take a closer look. Phyllis screams hysterically before embracing her. Pauline at first smiles proudly, but then begins to wail as she apparently realizes what she has done.


title: Excision (film)

text: "Excision" is Richard Bates, Jr.'s first feature film. Bates, a Virginia native and graduate of the New York University Tisch School of the Arts, filmed "Excision" over 28 days in and around Los Angeles, California.


title: Excision (film)

text: The review aggregation website Rotten Tomatoes gives the film a score of 84%, based on reviews from 25 critics, with an average rating of 6.56/10. The website's consensus reads, ""Excision" effectively blends body horror and adolescent drama, although its visceral aggression definitely isn't for all tastes."


title: Excision (film)

text: Robert Koehler of "Variety" called it "technically polished juvenilia that provokes without resonance". At "The A.V. Club", two critics reviewed it at Sundance. Noel Murray rated it B+ and wrote, "This is one of the damnedest 'adolescent misfit' movies you'll ever see—for those who can stomach the splatter, that is." Nathan Rabin rated it B+ and called it "a supremely nasty piece of work in the best way possible." Steve Rose of "The Guardian" rated it 2/5 stars and wrote, "This body-horror teen effort could have [been] Cronenberg meets Solondz – but it isn't". Witney Seibold of IGN rated it 7.5/10 and wrote, ""Excision" is twisted, ballsy, nasty, kind of gross, and more than a little bit disturbing." Streiber states it "revels a little too much in its gore" and seems as though it is a splatter film "only intended to shock", though the ending "clearly accentuates the tragedy of its clearly insane main character."


title: Computer chess

text: Computer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysis, entertainment and training.


title: Computer chess

text: Computer chess applications that play at the level of a chess master or higher are available on hardware from supercomputers to smart phones. Standalone chess-playing machines are also available. Stockfish, GNU Chess, Fruit, and other free open source applications are available for various platforms.


title: Computer chess

text: Computer chess applications, whether implemented in hardware or software, utilize different strategies than humans to choose their moves: they use heuristic methods to build, search and evaluate trees representing sequences of moves from the current position and attempt to execute the best such sequence during play. Such trees are typically quite large, thousands to millions of nodes. The computational speed of modern computers, capable of processing tens of thousands to hundreds of thousands of nodes or more per second, along with extension and reduction heuristics that narrow the tree to mostly relevant nodes, make such an approach effective.


title: Computer chess

text: The first chess machines capable of playing chess or reduced chess-like games were software programs running on digital computers early in the vacuum-tube computer age (1950s). The early programs played so poorly that even a beginner could defeat them. Within 40 years, in 1997, chess engines running on super-computers or specialized hardware were capable of defeating even the best human players. By 2006, programs running on desktop PCs had attained the same capability. In 2006, Monroe Newborn, Professor of Computer Science at McGill University, declared: "the science has been done". Nevertheless, solving chess is not currently possible for modern computers due to the game's extremely large number of possible variations.


title: Computer chess

text: Computer chess was once considered the "Drosophila of AI", the edge of knowledge engineering. But the field is now considered a scientifically completed paradigm, and playing chess is a mundane computing activity.


title: Computer chess

text: Chess machines/programs are available in several different forms: stand-alone chess machines (usually a microprocessor running a software chess program, but sometimes as a specialized hardware machine), software programs running on standard PCs, web sites, and apps for mobile devices. Programs run on everything from super-computers to smartphones. Hardware requirements for programs are minimal; the apps are no larger than a few megabytes on disk, use a few megabytes of memory (but can use much more, if it is available), and any processor 300Mhz or faster is sufficient. Performance will vary modestly with processor speed, but sufficient memory to hold a large transposition table (up to several gigabytes or more) is more important to playing strength than processor speed.


title: Computer chess

text: Most available commercial chess programs and machines can play at super-grandmaster strength (Elo 2700 or more), and take advantage of multi-core and hyperthreaded computer CPU architectures. Top programs such as Stockfish have surpassed even world champion caliber players. Most chess programs comprise a chess engine connected to a GUI, such as Winboard or Chessbase. Playing strength, time controls, and other performance-related settings are adjustable from the GUI. Most GUIs also allow the player to set up and to edit positions, to reverse moves, to offer and to accept draws (and resign), to request and to receive move recommendations, and to show the engine's analysis as the game progresses.


title: Computer chess

text: There are a few chess engines such as Sargon, IPPOLIT, Stockfish, Crafty, Fruit, Leela Chess Zero and GNU Chess which can be downloaded (or source code otherwise obtained) from the Internet free of charge.


title: Computer chess

text: Perhaps the most common type of chess software are programs that simply play chess. A human player makes a move on the board, the AI calculates and plays a subsequent move, and the human and AI alternate turns until the game ends. The chess engine, which calculates the moves, and the graphical user interface (GUI) are sometimes separate programs. Different engines can be connected to the GUI, permitting play against different styles of opponent. Engines often have a simple text command-line interface, while GUIs may offer a variety of piece sets, board styles, or even 3D or animated pieces. Because recent engines are so capable, engines or GUIs may offer some way of handicapping the engine's ability, to improve the odds for a win by the human player. Universal Chess Interface (UCI) engines such Fritz or Rybka may have a built in mechanism for reducing the Elo rating of the engine (via UCI's uci_limitstrength and uci_elo parameters). Some versions of Fritz have a Handicap and Fun mode for limiting the current engine or changing the percentage of mistakes it makes or changing its style. Fritz also has a Friend Mode where during the game it tries to match the level of the player.


title: Computer chess

text: Chess databases allow users to search through a large library of historical games, analyze them, check statistics, and formulate an opening repertoire. Chessbase (for PC) is a common program for these purposes amongst professional players, but there are alternatives such as Shane's Chess Information Database (Scid) for Windows, Mac or Linux, Chess Assistant for PC, Gerhard Kalab's Chess PGN Master for Android or Giordano Vicoli's Chess-Studio for iOS.


title: Computer chess

text: Chess training programs teach chess. Chessmaster had playthrough tutorials by IM Josh Waitzkin and GM Larry Christiansen. Stefan Meyer-Kahlen offers Shredder Chess Tutor based on the Step coursebooks of Rob Brunia and Cor Van Wijgerden. World champions Magnus Carlsen's Play Magnus company released a Magnus Trainer app for Android and iOS. Chessbase has Fritz and Chesster for children. Convekta provides a large number of training apps such as CT-ART and its Chess King line based on tutorials by GM Alexander Kalinin and Maxim Blokh.


title: Computer chess

text: After discovering refutation screening—the application of alpha–beta pruning to optimizing move evaluation—in 1957, a team at Carnegie Mellon University predicted that a computer would defeat the world human champion by 1967. It did not anticipate the difficulty of determining the right order to evaluate moves. Researchers worked to improve programs' ability to identify killer heuristics, unusually high-scoring moves to reexamine when evaluating other branches, but into the 1970s most top chess players believed that computers would not soon be able to play at a Master level. In 1968 International Master David Levy made a famous bet that no chess computer would be able to beat him within ten years, and in 1976 Senior Master and professor of psychology Eliot Hearst of Indiana University wrote that "the only way a current computer program could ever win a single game against a master player would be for the master, perhaps in a drunken stupor while playing 50 games simultaneously, to commit some once-in-a-year blunder".


title: Computer chess

text: In the late 1970s chess programs suddenly began defeating highly skilled human players. The year of Hearst's statement, Northwestern University's Chess 4.5 at the Paul Masson American Chess Championship's Class B level became the first to win a human tournament. Levy won his bet in 1978 by beating Chess 4.7, but it achieved the first computer victory against a Master-class player at the tournament level by winning one of the six games. In 1980 Belle began often defeating Masters. By 1982 two programs played at Master level and three were slightly weaker.


title: Computer chess

text: The sudden improvement without a theoretical breakthrough was unexpected, as many did not expect that Belle's ability to examine 100,000 positions a second—about eight plies—would be sufficient. The Spracklens, creators of the successful microcomputer program "Sargon", estimated that 90% of the improvement came from faster evaluation speed and only 10% from improved evaluations. "New Scientist" stated in 1982 that computers "play "terrible" chess ... clumsy, inefficient, diffuse, and just plain ugly", but humans lost to them by making "horrible blunders, astonishing lapses, incomprehensible oversights, gross miscalculations, and the like" much more often than they realized; "in short, computers win primarily through their ability to find and exploit miscalculations in human initiatives".


title: Computer chess

text: By 1982, microcomputer chess programs could evaluate up to 1,500 moves a second and were as strong as mainframe chess programs of five years earlier, able to defeat a majority of amateur players. While only able to look ahead one or two plies more than at their debut in the mid-1970s, doing so improved their play more than experts expected; seemingly minor improvements "appear to have allowed the crossing of a psychological threshold, after which a rich harvest of human error becomes accessible", "New Scientist" wrote. While reviewing "SPOC" in 1984, "BYTE" wrote that "Computers—mainframes, minis, and micros—tend to play ugly, inelegant chess", but noted Robert Byrne's statement that "tactically they are freer from error than the average human player". The magazine described "SPOC" as a "state-of-the-art chess program" for the IBM PC with a "surprisingly high" level of play, and estimated its USCF rating as 1700 (Class B).


title: Computer chess

text: At the 1982 North American Computer Chess Championship, Monroe Newborn predicted that a chess program could become world champion within five years; tournament director and International Master Michael Valvo predicted ten years; the Spracklens predicted 15; Ken Thompson predicted more than 20; and others predicted that it would never happen. The most widely held opinion, however, stated that it would occur around the year 2000. In 1989, Levy was defeated by Deep Thought in an exhibition match. Deep Thought, however, was still considerably below World Championship level, as the reigning world champion, Garry Kasparov, demonstrated in two strong wins in 1989. It was not until a 1996 match with IBM's Deep Blue that Kasparov lost his first game to a computer at tournament time controls in Deep Blue versus Kasparov, 1996, game 1. This game was, in fact, the first time a reigning world champion had lost to a computer using regular time controls. However, Kasparov regrouped to win three and draw two of the remaining five games of the match, for a convincing victory.


title: Computer chess

text: In May 1997, an updated version of Deep Blue defeated Kasparov 3½–2½ in a return match. A documentary mainly about the confrontation was made in 2003, titled "".


title: Computer chess

text: With increasing processing power and improved evaluation functions, chess programs running on commercially available workstations began to rival top flight players. In 1998, Rebel 10 defeated Viswanathan Anand, who at the time was ranked second in the world, by a score of 5–3. However, most of those games were not played at normal time controls. Out of the eight games, four were blitz games (five minutes plus five seconds Fischer delay for each move); these Rebel won 3–1. Two were semi-blitz games (fifteen minutes for each side) that Rebel won as well (1½–½). Finally, two games were played as regular tournament games (forty moves in two hours, one hour sudden death); here it was Anand who won ½–1½. In fast games, computers played better than humans, but at classical time controls – at which a player's rating is determined – the advantage was not so clear.


title: Computer chess

text: In the early 2000s, commercially available programs such as Junior and Fritz were able to draw matches against former world champion Garry Kasparov and classical world champion Vladimir Kramnik.


title: Computer chess

text: In October 2002, Vladimir Kramnik and Deep Fritz competed in the eight-game Brains in Bahrain match, which ended in a draw. Kramnik won games 2 and 3 by "conventional" anti-computer tactics – play conservatively for a long-term advantage the computer is not able to see in its game tree search. Fritz, however, won game 5 after a severe blunder by Kramnik. Game 6 was described by the tournament commentators as "spectacular". Kramnik, in a better position in the early middlegame, tried a piece sacrifice to achieve a strong tactical attack, a strategy known to be highly risky against computers who are at their strongest defending against such attacks. True to form, Fritz found a watertight defense and Kramnik's attack petered out leaving him in a bad position. Kramnik resigned the game, believing the position lost. However, post-game human and computer analysis has shown that the Fritz program was unlikely to have been able to force a win and Kramnik effectively sacrificed a drawn position. The final two games were draws. Given the circumstances, most commentators still rate Kramnik the stronger player in the match.


title: Computer chess

text: In January 2003, Kasparov played Junior, another chess computer program, in New York City. The match ended 3–3.


title: Computer chess

text: In 2005, Hydra, a dedicated chess computer with custom hardware and sixty-four processors and also winner of the 14th IPCCC in 2005, defeated seventh-ranked Michael Adams 5½–½ in a six-game match (though Adams' preparation was far less thorough than Kramnik's for the 2002 series).


title: Computer chess

text: In November–December 2006, World Champion Vladimir Kramnik played Deep Fritz. This time the computer won; the match ended 2–4. Kramnik was able to view the computer's opening book. In the first five games Kramnik steered the game into a typical "anti-computer" positional contest. He lost one game (overlooking a mate in one), and drew the next four. In the final game, in an attempt to draw the match, Kramnik played the more aggressive Sicilian Defence and was crushed.


title: Computer chess

text: There was speculation that interest in human–computer chess competition would plummet as a result of the 2006 Kramnik-Deep Fritz match. According to Newborn, for example, "the science is done".


title: Computer chess

text: Human–computer chess matches showed the best computer systems overtaking human chess champions in the late 1990s. For the 40 years prior to that, the trend had been that the best machines gained about 40 points per year in the Elo rating while the best humans only gained roughly 2 points per year. The highest rating obtained by a computer in human competition was Deep Thought's USCF rating of 2551 in 1988 and FIDE no longer accepts human–computer results in their rating lists. Specialized machine-only Elo pools have been created for rating machines, but such numbers, while similar in appearance, are not directly compared. In 2016, the Swedish Chess Computer Association rated computer program Komodo at 3361.


title: Computer chess

text: Chess engines continue to improve. In 2009, chess engines running on slower hardware have reached the grandmaster level. A mobile phone won a category 6 tournament with a performance rating 2898: chess engine Hiarcs 13 running inside Pocket Fritz 4 on the mobile phone HTC Touch HD won the Copa Mercosur tournament in Buenos Aires, Argentina with 9 wins and 1 draw on August 4–14, 2009. Pocket Fritz 4 searches fewer than 20,000 positions per second. This is in contrast to supercomputers such as Deep Blue that searched 200 million positions per second.


title: Computer chess

text: Advanced Chess is a form of chess developed in 1998 by Kasparov where a human plays against another human, and both have access to computers to enhance their strength. The resulting "advanced" player was argued by Kasparov to be stronger than a human or computer alone. This has been proven in numerous occasions, such as at Freestyle Chess events.


title: Computer chess

text: Players today are inclined to treat chess engines as analysis tools rather than opponents. Chess grandmaster Andrew Soltis stated in 2016 "The computers are just much too good" and that world champion Magnus Carlsen won't play computer chess because "he just loses all the time and there's nothing more depressing than losing without even being in the game."


title: Computer chess

text: Since the era of mechanical machines that played rook and king endings and electrical machines that played other games like hex in the early years of the 20th century, scientists and theoreticians have sought to develop a procedural representation of how humans learn, remember, think and apply knowledge, and the game of chess, because of its daunting complexity, became the "Drosophila of artificial intelligence (AI)". The procedural resolution of complexity became synonymous with thinking, and early computers, even before the chess automaton era, were popularly referred to as "electronic brains". Several different schema were devised starting in the latter half of the 20th century to represent knowledge and thinking, as applied to playing the game of chess (and other games like checkers):


title: Computer chess

text: Using "ends-and-means" heuristics a human chess player can intuitively determine optimal outcomes and how to achieve them regardless of the number of moves necessary, but a computer must be systematic in its analysis. Most players agree that looking at least five moves ahead (ten plies) when necessary is required to play well. Normal tournament rules give each player an average of three minutes per move. On average there are more than 30 legal moves per chess position, so a computer must examine a quadrillion possibilities to look ahead ten plies (five full moves); one that could examine a million positions a second would require more than 30 years.


title: Computer chess

text: The earliest attempts at procedural representations of playing chess predated the digital electronic age, but it was the stored program digital computer that gave scope to calculating such complexity. Claude Shannon, in 1949, laid out the principles of algorithmic solution of chess. In that paper, the game is represented by a "tree", or digital data structure of choices (branches) corresponding to moves. The nodes of the tree were positions on the board resulting from the choices of move. The impossibility of representing an entire game of chess by constructing a tree from first move to last was immediately apparent: there are an average of 36 moves per position in chess and an average game lasts about 35 moves to resignation (60-80 moves if played to checkmate, stalemate, or other draw). There are 400 positions possible after the first move by each player, about 200,000 after two moves each, and nearly 120 million after just 3 moves each.


title: Computer chess

text: So a limited lookahead (search) to some depth, followed by using domain-specific knowledge to evaluate the resulting terminal positions was proposed. A kind of middle-ground position, given good moves by both sides, would result, and its evaluation would inform the player about the goodness or badness of the moves chosen. Searching and comparing operations on the tree were well suited to computer calculation; the representation of subtle chess knowledge in the evaluation function was not. The early chess programs suffered in both areas: searching the vast tree required computational resources far beyond those available, and what chess knowledge was useful and how it was to be encoded would take decades to discover.


title: Computer chess

text: The developers of a chess-playing computer system must decide on a number of fundamental implementation issues. These include:


title: Computer chess

text: Adriaan de Groot interviewed a number of chess players of varying strengths, and concluded that both masters and beginners look at around forty to fifty positions before deciding which move to play. What makes the former much better players is that they use pattern recognition skills built from experience. This enables them to examine some lines in much greater depth than others by simply not considering moves they can assume to be poor. More evidence for this being the case is the way that good human players find it much easier to recall positions from genuine chess games, breaking them down into a small number of recognizable sub-positions, rather than completely random arrangements of the same pieces. In contrast, poor players have the same level of recall for both.


title: Computer chess

text: The equivalent of this in computer chess are evaluation functions for leaf evaluation, which correspond to the human players' pattern recognition skills, and the use of machine learning techniques in training them, such as Texel tuning, stochastic gradient descent, and reinforcement learning, which corresponds to building experience in human players. This allows modern programs to examine some lines in much greater depth than others by using forwards pruning and other selective heuristics to simply not consider moves the program assume to be poor through their evaluation function, in the same way that human players do. The only fundamental difference between a computer program and a human in this sense is that a computer program can search much deeper than a human player could, allowing it to search more nodes and bypass the horizon effect to a much greater extent than is possible with human players.


title: Computer chess

text: Computer chess programs usually support a number of common "de facto" standards. Nearly all of today's programs can read and write game moves as Portable Game Notation (PGN), and can read and write individual positions as Forsyth–Edwards Notation (FEN). Older chess programs often only understood long algebraic notation, but today users expect chess programs to understand standard algebraic chess notation.


title: Computer chess

text: Starting in the late 1990s, programmers began to develop separately "engines" (with a command-line interface which calculates which moves are strongest in a position) or a "graphical user interface" (GUI) which provides the player with a chessboard they can see, and pieces that can be moved. Engines communicate their moves to the GUI using a protocol such as the Chess Engine Communication Protocol (CECP) or Universal Chess Interface (UCI). By dividing chess programs into these two pieces, developers can write only the user interface, or only the engine, without needing to write both parts of the program. (See also chess engine.)


title: Computer chess

text: Developers have to decide whether to connect the engine to an opening book and/or endgame tablebases or leave this to the GUI.


title: Computer chess

text: The data structure used to represent each chess position is key to the performance of move generation and position evaluation. Methods include pieces stored in an array ("mailbox" and "0x88"), piece positions stored in a list ("piece list"), collections of bit-sets for piece locations ("bitboards"), and huffman coded positions for compact long-term storage.


title: Computer chess

text: Computer chess programs consider chess moves as a game tree. In theory, they examine all moves, then all counter-moves to those moves, then all moves countering them, and so on, where each individual move by one player is called a "ply". This evaluation continues until a certain maximum search depth or the program determines that a final "leaf" position has been reached (e.g. checkmate).


title: Computer chess

text: One particular type of search algorithm used in computer chess are minimax search algorithms, where at each ply the "best" move by the player is selected; one player is trying to maximize the score, the other to minimize it. By this alternating process, one particular terminal node whose evaluation represents the searched value of the position will be arrived at. Its value is backed up to the root, and that evaluation becomes the valuation of the position on the board. This search process is called minimax.


title: Computer chess

text: A naive implementation of the minimax algorithm can only search to a small depth in a practical amount of time, so various methods have been devised to greatly speed the search for good moves. Alpha–beta pruning, a system of defining upper and lower bounds on possible search results and searching until the bounds coincided, is typically used to reduce the search space of the program.


title: Computer chess

text: In addition, various selective search heuristics, such as quiescence search, forward pruning, search extensions and search reductions, are also used as well. These heuristics are triggered based on certain conditions in an attempt to weed out obviously bad moves (history moves) or to investigate interesting nodes (e.g. check extensions, passed pawns on seventh rank, etc.). These selective search heuristics have to be used very carefully however. Over extend and the program wastes too much time looking at uninteresting positions. If too much is pruned or reduced, there is a risk cutting out interesting nodes.


title: Computer chess

text: Monte Carlo tree search (MCTS) is a heuristic search algorithm which expands the search tree based on random sampling of the search space. A version of Monte Carlo tree search commonly used in computer chess is PUCT, Predictor and Upper Confidence bounds applied to Trees.


title: Computer chess

text: DeepMind's AlphaZero and Leela Chess Zero uses MCTS instead of minimax. Such engines use batching on graphics processing units in order to calculate their evaluation functions and policy (move selection), and therefore require a parallel search algorithm as calculations on the GPU are inherently parallel. The minimax and alpha-beta pruning algorithms used in computer chess are inherently serial algorithms, so would not work well with batching on the GPU. On the other hand, MCTS is a good alternative, because the random sampling used in Monte Carlo tree search lends itself well to parallel computing, and is why nearly all engines which support calculations on the GPU use MCTS instead of alpha-beta.


title: Computer chess

text: Many other optimizations can be used to make chess-playing programs stronger. For example, transposition tables are used to record positions that have been previously evaluated, to save recalculation of them. Refutation tables record key moves that "refute" what appears to be a good move; these are typically tried first in variant positions (since a move that refutes one position is likely to refute another). The drawback is that transposition tables at deep ply depths can get quite large – tens to hundreds of millions of entries. IBM's Deep Blue transposition table in 1996, for example was 500 million entries. Transposition tables that are too small can result in spending more time searching for non-existent entries due to threshing than the time saved by entries found. Many chess engines use pondering, searching to deeper levels on the opponent's time, similar to human beings, to increase their playing strength.


title: Computer chess

text: Of course, faster hardware and additional memory can improve chess program playing strength. Hyperthreaded architectures can improve performance modestly if the program is running on a single core or a small number of cores. Most modern programs are designed to take advantage of multiple cores to do parallel search. Other programs are designed to run on a general purpose computer and allocate move generation, parallel search, or evaluation to dedicated processors or specialized co-processors.


title: Computer chess

text: The first paper on search was by Claude Shannon in 1950. He predicted the two main possible search strategies which would be used, which he labeled "Type A" and "Type B", before anyone had programmed a computer to play chess.


title: Computer chess

text: Type A programs would use a "brute force" approach, examining every possible position for a fixed number of moves using a pure naive minimax algorithm. Shannon believed this would be impractical for two reasons.


title: Computer chess

text: First, with approximately thirty moves possible in a typical real-life position, he expected that searching the approximately 10 positions involved in looking three moves ahead for both sides (six plies) would take about sixteen minutes, even in the "very optimistic" case that the chess computer evaluated a million positions every second. (It took about forty years to achieve this speed. An later search algorithm called alpha–beta pruning, a system of defining upper and lower bounds on possible search results and searching until the bounds coincided, reduced the branching factor of the game tree logarithmically, but it still was not feasible for chess programs at the time to exploit the exponential explosion of the tree.


title: Computer chess

text: Second, it ignored the problem of quiescence, trying to only evaluate a position that is at the end of an exchange of pieces or other important sequence of moves ('lines'). He expected that adapting minimax to cope with this would greatly increase the number of positions needing to be looked at and slow the program down still further. He expected that adapting type A to cope with this would greatly increase the number of positions needing to be looked at and slow the program down still further.


title: Computer chess

text: This led naturally to what is referred to as "selective search" or "type B search", using chess knowledge (heuristics) to select a few presumably good moves from each position to search, and prune away the others without searching. Instead of wasting processing power examining bad or trivial moves, Shannon suggested that type B programs would use two improvements:


title: Computer chess

text: This would enable them to look further ahead ('deeper') at the most significant lines in a reasonable time.


title: Computer chess

text: However, early attempts at selective search often resulted in the best move or moves being pruned away. As a result, little or no progress was made for the next 25 years dominated by this first iteration of the selective search paradigm. The best program produced in this early period was Mac Hack VI in 1967; it played at the about the same level as the average amateur (C class on the United States Chess Federation rating scale).


title: Computer chess

text: Meanwhile, hardware continued to improve, and in 1974, brute force searching was implemented for the first time in the Northwestern University Chess 4.0 program. In this approach, all alternative moves at a node are searched, and none are pruned away. They discovered that the time required to simply search all the moves was much less than the time required to apply knowledge-intensive heuristics to select just a few of them, and the benefit of not prematurely or inadvertently pruning away good moves resulted in substantially stronger performance.


title: Computer chess

text: In the 1980s and 1990s, progress was finally made in the selective search paradigm, with the development of quiescence search, null move pruning, and other modern selective search heuristics. These heuristics had far fewer mistakes than earlier heuristics did, and was found to be worth the extra time it saved because it could search deeper and widely adopted by many engines. While many modern programs do use alpha-beta search as a substrate for their search algorithm, these additional selective search heuristics used in modern programs means that the program no longer does a "brute force" search. Instead they heavily rely on these selective search heuristics to extend lines the program considers good and prune and reduce lines the program considers bad, to the point where most of the nodes on the search tree are pruned away, enabling modern programs to search very deep.


title: Computer chess

text: In 2006, Rémi Coulom created Monte Carlo tree search, another kind of type B selective search. In 2007, an adaption of Monte Carlo tree search called Upper Confidence bounds applied to Trees or UCT for short was created by Levente Kocsis and Csaba Szepesvári. In 2011, Chris Rosin developed a variation of UCT called Predictor + Upper Confidence bounds applied to Trees, or PUCT for short. PUCT was then used in AlphaZero in 2017, and later in Leela Chess Zero in 2018.


title: Computer chess

text: In the 1970s, most chess programs ran on super computers like Control Data Cyber 176s or Cray-1s, indicative that during that developmental period for computer chess, processing power was the limiting factor in performance. Most chess programs struggled to search to a depth greater than 3 ply. It was not until the hardware chess machines of the 1980s, that a relationship between processor speed and knowledge encoded in the evaluation function became apparent.


title: Computer chess

text: It has been estimated that doubling the computer speed gains approximately fifty to seventy Elo points in playing strength .


title: Computer chess

text: For most chess positions, computers cannot look ahead to all possible final positions. Instead, they must look ahead a few plies and compare the possible positions, known as leaves. The algorithm that evaluates leaves is termed the "evaluation function", and these algorithms are often vastly different between different chess programs. Evaluation functions typically evaluate positions in hundredths of a pawn (called a centipawn), where by convention, a positive evaluation favors White, and a negative evaluation favors Black. However, some evaluation function output win/draw/loss percentages instead of centipawns.


title: Computer chess

text: Historically, handcrafted evaluation functions consider material value along with other factors affecting the strength of each side. When counting up the material for each side, typical values for pieces are 1 point for a pawn, 3 points for a knight or bishop, 5 points for a rook, and 9 points for a queen. (See Chess piece relative value.) The king is sometimes given an arbitrary high value such as 200 points (Shannon's paper) to ensure that a checkmate outweighs all other factors . In addition to points for pieces, most handcrafted evaluation functions take many factors into account, such as pawn structure, the fact that a pair of bishops are usually worth more, centralized pieces are worth more, and so on. The protection of kings is usually considered, as well as the phase of the game (opening, middle or endgame). Machine learning techniques such as Texel turning, stochastic gradient descent, or reinforcement learning are usually used to optimise handcrafted evaluation functions.


title: Computer chess

text: Most modern evaluation functions make use of neural networks. The most common evaluation function in use today is the efficiently updatable neural network, which is a shallow neural network whose inputs are piece-square tables. Piece-square tables are a set of 64 values corresponding to the squares of the chessboard, and there typically exists a piece-square table for every piece and colour, resulting in 12 piece-square tables and thus 768 inputs into the neural network. In addition, some engines use deep neural networks in their evaluation function. Neural networks are usually trained using some reinforcement learning algorithm, in conjunction with supervised learning or unsupervised learning.


title: Computer chess

text: The output of the evaluation function is a single scalar, quantized in centipawns or other units, which is, in the case of handcrafted evaluation functions, a weighted summation of the various factors described, or in the case of neural network based evaluation functions, the output of the head of the neural network. The evaluation putatively represents or approximates the value of the subtree below the evaluated node as if it had been searched to termination, i.e. the end of the game. During the search, an evaluation is compared against evaluations of other leaves, eliminating nodes that represent bad or poor moves for either side, to yield a node which by convergence, represents the value of the position with best play by both sides.


title: Computer chess

text: Endgame play had long been one of the great weaknesses of chess programs because of the depth of search needed. Some otherwise master-level programs were unable to win in positions where even intermediate human players could force a win.


title: Computer chess

text: To solve this problem, computers have been used to analyze some chess endgame positions completely, starting with king and pawn against king. Such endgame tablebases are generated in advance using a form of retrograde analysis, starting with positions where the final result is known (e.g., where one side has been mated) and seeing which other positions are one move away from them, then which are one move from those, etc. Ken Thompson was a pioneer in this area.


title: Computer chess

text: The results of the computer analysis sometimes surprised people. In 1977 Thompson's Belle chess machine used the endgame tablebase for a king and rook against king and queen and was able to draw that theoretically lost ending against several masters (see Philidor position#Queen versus rook). This was despite not following the usual strategy to delay defeat by keeping the defending king and rook close together for as long as possible. Asked to explain the reasons behind some of the program's moves, Thompson was unable to do so beyond saying the program's database simply returned the best moves.


title: Computer chess

text: Most grandmasters declined to play against the computer in the queen versus rook endgame, but Walter Browne accepted the challenge. A queen versus rook position was set up in which the queen can win in thirty moves, with perfect play. Browne was allowed 2½ hours to play fifty moves, otherwise a draw would be claimed under the fifty-move rule. After forty-five moves, Browne agreed to a draw, being unable to force checkmate or win the rook within the next five moves. In the final position, Browne was still seventeen moves away from checkmate, but not quite that far away from winning the rook. Browne studied the endgame, and played the computer again a week later in a different position in which the queen can win in thirty moves. This time, he captured the rook on the fiftieth move, giving him a winning position , .


title: Computer chess

text: Other positions, long believed to be won, turned out to take more moves against perfect play to actually win than were allowed by chess's fifty-move rule. As a consequence, for some years the official FIDE rules of chess were changed to extend the number of moves allowed in these endings. After a while, the rule reverted to fifty moves in all positions more such positions were discovered, complicating the rule still further, and it made no difference in human play, as they could not play the positions perfectly.


title: Computer chess

text: Over the years, other endgame database formats have been released including the Edward Tablebase, the De Koning Database and the Nalimov Tablebase which is used by many chess programs such as Rybka, Shredder and Fritz. Tablebases for all positions with six pieces are available. Some seven-piece endgames have been analyzed by Marc Bourzutschky and Yakov Konoval. Programmers using the Lomonosov supercomputers in Moscow have completed a chess tablebase for all endgames with seven pieces or fewer (trivial endgame positions are excluded, such as six white pieces versus a lone black king). In all of these endgame databases it is assumed that castling is no longer possible.


title: Computer chess

text: Many tablebases do not consider the fifty-move rule, under which a game where fifty moves pass without a capture or pawn move can be claimed to be a draw by either player. This results in the tablebase returning results such as "Forced mate in sixty-six moves" in some positions which would actually be drawn because of the fifty-move rule. One reason for this is that if the rules of chess were to be changed once more, giving more time to win such positions, it will not be necessary to regenerate all the tablebases. It is also very easy for the program using the tablebases to notice and take account of this 'feature' and in any case if using an endgame tablebase will choose the move that leads to the quickest win (even if it would fall foul of the fifty-move rule with perfect play). If playing an opponent not using a tablebase, such a choice will give good chances of winning within fifty moves.


title: Computer chess

text: The Nalimov tablebases, which use state-of-the-art compression techniques, require 7.05 GB of hard disk space for all five-piece endings. To cover all the six-piece endings requires approximately 1.2 TB. It is estimated that a seven-piece tablebase requires between 50 and 200 TB of storage space.


title: Computer chess

text: Endgame databases featured prominently in 1999, when Kasparov played an exhibition match on the Internet against the rest of the world. A seven piece Queen and pawn endgame was reached with the World Team fighting to salvage a draw. Eugene Nalimov helped by generating the six piece ending tablebase where both sides had two Queens which was used heavily to aid analysis by both sides.


title: Computer chess

text: Chess engines, like human beings, may save processing time as well as select strong variations as expounded by the masters, by referencing an opening book stored in a disk database. Opening books cover the opening moves of a game to variable depth, depending on opening and variation, but usually to the first 10-12 moves (20-24 ply). Since the openings have been studied in depth by the masters for centuries, and some are known to well into the middle game, the valuations of specific variations by the masters will usually be superior to the general heuristics of the program.


title: Computer chess

text: While at one time, playing an out-of-book move in order to put the chess program onto its own resources might have been an effective strategy because chess opening books were selective to the program's playing style, and programs had notable weaknesses relative to humans, that is no longer true today. The opening books stored in computer databases are most likely far more extensive than even the best prepared humans, and playing an early out-of-book move may result in the computer finding the unusual move in its book and saddling the opponent with a sharp disadvantage. Even if it does not, playing out-of-book may be much better for tactically sharp chess programs than for humans who have to discover strong moves in an unfamiliar variation over the board.


title: Computer chess

text: CEGT, CSS, SSDF, WBEC, REBEL, FGRL, and IPON maintain rating lists allowing fans to compare the strength of engines. Various versions of Stockfish, Komodo, Leela Chess Zero, and Fat Fritz dominate the rating lists in the early 2020s.


title: Computer chess

text: CCRL (Computer Chess Rating Lists) is an organisation that tests computer chess engines' strength by playing the programs against each other. CCRL was founded in 2006 to promote computer-computer competition and tabulate results on a rating list.


title: Computer chess

text: The organisation runs three different lists: 40/40 (40 minutes for every 40 moves played), 40/4 (4 minutes for every 40 moves played), and 40/4 FRC (same time control but Chess960). Pondering (or permanent brain) is switched off and timing is adjusted to the AMD64 X2 4600+ (2.4 GHz) CPU by using Crafty 19.17 BH as a benchmark. Generic, neutral opening books are used (as opposed to the engine's own book) up to a limit of 12 moves into the game alongside 4 or 5 man tablebases.


title: Computer chess

text: The idea of creating a chess-playing machine dates back to the eighteenth century. Around 1769, the chess playing automaton called The Turk, created by Hungarian inventor Farkas Kempelen, became famous before being exposed as a hoax. Before the development of digital computing, serious trials based on automata such as El Ajedrecista of 1912 which played a king and rook versus king ending, were too complex and limited to be useful for playing full games of chess. The field of mechanical chess research languished until the advent of the digital computer in the 1950s.


title: Computer chess

text: Since then, chess enthusiasts and computer engineers have built, with increasing degrees of seriousness and success, chess-playing machines and computer programs. One of the few chess grandmasters to devote himself seriously to computer chess was former World Chess Champion Mikhail Botvinnik, who wrote several works on the subject. He also held a doctorate in electrical engineering. Working with relatively primitive hardware available in the Soviet Union in the early 1960s, Botvinnik had no choice but to investigate software move selection techniques; at the time only the most powerful computers could achieve much beyond a three-ply full-width search, and Botvinnik had no such machines. In 1965 Botvinnik was a consultant to the ITEP team in a US-Soviet computer chess match (see Kotok-McCarthy).


title: Computer chess

text: One developmental milestone occurred when the team from Northwestern University, which was responsible for the Chess series of programs and won the first three ACM Computer Chess Championships (1970–72), abandoned type B searching in 1973. The resulting program, Chess 4.0, won that year's championship and its successors went on to come in second in both the 1974 ACM Championship and that year's inaugural World Computer Chess Championship, before winning the ACM Championship again in 1975, 1976 and 1977. The type A implementation turned out to be just as fast: in the time it used to take to decide which moves were worthy of being searched, it was possible just to search all of them. In fact, Chess 4.0 set the paradigm that was and still is followed essentially by all modern Chess programs today.


title: Computer chess

text: In 1978, an early rendition of Ken Thompson's hardware chess machine Belle, entered and won the North American Computer Chess Championship over the dominant Northwestern University Chess 4.7.


title: Computer chess

text: Technological advances by orders of magnitude in processing power have made the brute force approach far more incisive than was the case in the early years. The result is that a very solid, tactical AI player aided by some limited positional knowledge built in by the evaluation function and pruning/extension rules began to match the best players in the world. It turned out to produce excellent results, at least in the field of chess, to let computers do what they do best (calculate) rather than coax them into imitating human thought processes and knowledge. In 1997 Deep Blue, a brute-force machine capable of examining 500 million nodes per second, defeated World Champion Garry Kasparov, marking the first time a computer has defeated a reigning world chess champion in standard time control.


title: Computer chess

text: In 2016, NPR asked experts to characterize the playing style of computer chess engines. Murray Campbell of IBM stated that "Computers don't have any sense of aesthetics... They play what they think is the objectively best move in any position, even if it looks absurd, and they can play any move no matter how ugly it is." Grandmasters Andrew Soltis and Susan Polgar stated that computers are more likely to retreat than humans are.


title: Computer chess

text: While neural networks have been used in the evaluation functions of chess engines since the late 1980s, with programs such as NeuroChess, Morph, Blondie25, Giraffe, AlphaZero, and MuZero, neural networks did not become widely adopted by chess engines until the arrival of efficiently updatable neural networks in the summer of 2020. Efficiently updatable neural networks were originally developed in computer shogi in 2018 by Yu Nasu, and had to be first ported to a derivative of Stockfish called Stockfish NNUE on 31 May 2020, and integrated into the official Stockfish engine on 6 August 2020, before other chess programmers began to adopt neural networks into their engines.


title: Computer chess

text: Some people, such as the Royal Society's Venki Ramakrishnan, believe that AlphaZero lead to the widespread adoption of neural networks in chess engines. However, AlphaZero influenced very few engines to begin using neural networks, and those tended to be new experimental engines such as Leela Chess Zero, which began specifically to replicate the AlphaZero paper. The deep neural networks used in AlphaZero's evaluation function required expensive graphics processing units, which were not compatible with existing chess engines. The vast majority of chess engines only use central processing units, and computing and processing information on the GPUs require special libraries in the backend such as Nvidia's CUDA, which none of the engines had access to. Thus the vast majority of chess engines such as Komodo and Stockfish continued to use handcrafted evaluation functions until efficiently updatable neural networks were ported to computer chess in 2020, which did not require either the use of GPUs or libraries like CUDA at all. Even then, the neural networks used in computer chess are fairly shallow, and the deep reinforcement learning methods pioneered by AlphaZero are still extremely rare in computer chess.


title: Computer chess

text: These chess playing systems include custom hardware with approx. dates of introduction (excluding dedicated microcomputers):


title: Computer chess

text: In the late 1970s to early 1990s, there was a competitive market for dedicated chess computers. This market changed in the mid-1990s when computers with dedicated processors could no longer compete with the fast processors in personal computers.


title: Computer chess

text: Recently, some hobbyists have been using the Multi Emulator Super System to run the chess programs created for Fidelity or Hegener & Glaser's Mephisto computers on modern 64-bit operating systems such as Windows 10. The author of Rebel, Ed Schröder has also adapted three of the Hegener & Glaser Mephisto's he wrote to work as UCI engines.


title: Computer chess

text: These programs can be run on MS-DOS, and can be run on 64-bit Windows 10 via emulators such as DOSBox or Qemu:


title: Computer chess

text: The prospects of completely solving chess are generally considered to be rather remote. It is widely conjectured that there is no computationally inexpensive method to solve chess even in the very weak sense of determining with certainty the value of the initial position, and hence the idea of solving chess in the stronger sense of obtaining a practically usable description of a strategy for perfect play for either side seems unrealistic today. However, it has not been proven that no computationally cheap way of determining the best move in a chess position exists, nor even that a traditional alpha–beta searcher running on present-day computing hardware could not solve the initial position in an acceptable amount of time. The difficulty in proving the latter lies in the fact that, while the number of board positions that could happen in the course of a chess game is huge (on the order of at least 10 to 10), it is hard to rule out with mathematical certainty the possibility that the initial position allows either side to force a mate or a threefold repetition after relatively few moves, in which case the search tree might encompass only a very small subset of the set of possible positions. It has been mathematically proven that "generalized chess" (chess played with an arbitrarily large number of pieces on an arbitrarily large chessboard) is EXPTIME-complete, meaning that determining the winning side in an arbitrary position of generalized chess provably takes exponential time in the worst case; however, this theoretical result gives no lower bound on the amount of work required to solve ordinary 8x8 chess.


title: Computer chess

text: Martin Gardner's Minichess, played on a 5×5 board with approximately 10 possible board positions, has been solved; its game-theoretic value is 1/2 (i.e. a draw can be forced by either side), and the forcing strategy to achieve that result has been described.


title: Computer chess

text: Progress has also been made from the other side: as of 2012, all 7 and fewer pieces (2 kings and up to 5 other pieces) endgames have been solved.


title: Computer chess

text: A "chess engine" is software that calculates and orders which moves are the strongest to play in a given position. Engine authors focus on improving the play of their engines, often just importing the engine into a graphical user interface (GUI) developed by someone else. Engines communicate with the GUI by standardized protocols such as the nowadays ubiquitous Universal Chess Interface developed by Stefan Meyer-Kahlen and Franz Huber. There are others, like the Chess Engine Communication Protocol developed by Tim Mann for GNU Chess and Winboard. Chessbase has its own proprietary protocol, and at one time Millennium 2000 had another protocol used for ChessGenius. Engines designed for one operating system and protocol may be ported to other OS's or protocols.


title: Computer chess

text: In 1997, the Internet Chess Club released its first Java client for playing chess online against other people inside one's webbrowser. This was probably one of the first chess web apps. Free Internet Chess Server followed soon after with a similar client. In 2004, International Correspondence Chess Federation opened up a web server to replace their email-based system. Chess.com started offering Live Chess in 2007. Chessbase/Playchess has long had a downloadable client, and added a web-based client in 2013.


title: Computer chess

text: Another popular web app is tactics training. The now defunct Chess Tactics Server opened its site in 2006, followed by Chesstempo the next year, and Chess.com added its Tactics Trainer in 2008. Chessbase added a tactics trainer web app in 2015.


title: Computer chess

text: Chessbase took their chess game database online in 1998. Another early chess game databases was Chess Lab, which started in 1999. New In Chess had initially tried to compete with Chessbase by releasing a NICBase program for Windows 3.x, but eventually, decided to give up on software, and instead focus on their online database starting in 2002.


title: Computer chess

text: One could play against the engine Shredder online from 2006. In 2015, Chessbase added a play Fritz web app, as well as My Games for storing one's games.


title: Computer chess

text: Starting in 2007, Chess.com offered the content of the training program, Chess Mentor, to their customers online. Top GMs such as Sam Shankland and Walter Browne have contributed lessons.


title: Frederick II of Denmark

text: Frederick II (1 July 1534 – 4 April 1588) was King of Denmark and Norway and Duke of Schleswig and Holstein from 1559 until his death.


title: Frederick II of Denmark

text: A member of the House of Oldenburg, Frederick began his personal rule of Denmark-Norway at the age of 24. He inherited a capable and strong kingdom, formed in large by his father after the civil war known as the Count's Feud, after which Denmark saw a period of economic recovery and of a great increase in the centralised authority of the Crown.


title: Frederick II of Denmark

text: Frederick was, especially in his youth and unlike his father, belligerent and adversarial, aroused by honor and national pride, and so he began his reign auspiciously with a campaign under the aged Johan Rantzau, which reconquered Dithmarschen. However, after miscalculating the cost of the Northern Seven Years' War, he pursued a more prudent foreign policy. The remainder of Frederick II's reign was a period of tranquillity, in which king and nobles prospered. Frederick spent more time hunting and feasting with his councillors, and focused on architecture and science. During his reign, many building projects were begun, including additions to the royal castles of Kronborg at Elsinore and Frederikborg Castle at Hillerød.