Question: When was the American professional basketball player born who announced that he would leave the Thunder and sign with the Golden State Warriors?

Context paragraphs:
1980 NBA draft: The 1980 NBA draft was the 34th annual draft of the National Basketball Association (NBA).  The draft was held on June 10, 1980, before the 1980–81 season.  In this draft, 23 NBA teams took turns selecting amateur U.S. college basketball players and other eligible players, including international players.  The first two picks in the draft belonged to the teams that finished last in each conference, with the order determined by a coin flip.  The Boston Celtics, who obtained the Detroit Pistons' first-round pick in a trade, won the coin flip and were awarded the first overall pick, while the Utah Jazz were awarded the second pick.  The Celtics then traded the first pick to the Golden State Warriors before the draft.  The remaining first-round picks and the subsequent rounds were assigned to teams in reverse order of their win–loss record in the previous season.  An expansion franchise, the Dallas Mavericks, took part in the NBA Draft for the first time and were assigned the eleventh pick in each round.  A player who had finished his four-year college eligibility was automatically eligible for selection.  Before the draft, five college underclassmen announced that they would leave college early and would be eligible for selection.  The draft consisted of 10 rounds comprising the selection of 214 players.  This draft has the distinction of being the first NBA Draft to be televised.

Sam Williams (basketball, born 1959): Samuel Keith Williams (born March 7, 1959) is a former professional basketball player in the National Basketball Association (NBA).  He played four seasons in the NBA from 1981 through 1985 with the Golden State Warriors and the Philadelphia 76ers.  Williams played college basketball for the Arizona State Sun Devils, where he was an All-Pac-10 first team selection in 1981.  He was drafted in the 1981 NBA Draft in the second round with the 33rd overall pick by the Golden State Warriors.  Williams also played in the Continental Basketball Association in 1991-92 for the Bakersfield Jammers.

Shaun Livingston: Shaun Patrick Livingston (born September 11, 1985) is an American professional basketball player for the Golden State Warriors of the National Basketball Association (NBA).  Livingston entered the league directly out of high school after he was selected in the first round of the 2004 NBA draft by the Los Angeles Clippers with the 4th overall pick.  In 2007, Livingston suffered a debilitating knee injury that damaged almost every part of his left knee, and it took him about a year and a half to return to action.  Livingston later played for the Miami Heat, Oklahoma City Thunder, Washington Wizards, Charlotte Bobcats, Milwaukee Bucks, Cleveland Cavaliers, and Brooklyn Nets.  He has also spent time with the Tulsa 66ers of the NBA Development League.  He is a two-time NBA champion, winning both with Golden State in 2015 and 2017.

Kevin Durant: Kevin Wayne Durant (born September 29, 1988) is an American professional basketball player for the Golden State Warriors of the National Basketball Association (NBA).  He has won an NBA championship, an NBA Most Valuable Player Award, the Bill Russell NBA Finals Most Valuable Player Award, the NBA All-Star Game Most Valuable Player Award, four NBA scoring titles, the NBA Rookie of the Year Award, and two Olympic gold medals.  Durant has also been selected to seven All-NBA teams and eight NBA All-Star teams.

List of Golden State Warriors head coaches: The Golden State Warriors are an American professional basketball team based in Oakland, California.  The franchise had been known as the Philadelphia Warriors and the San Francisco Warriors, due to it previously being based in or near those cities.  The team is a member of the Pacific Division of the Western Conference in the National Basketball Association (NBA).  The Warriors initially joined the Basketball Association of America (BAA) as the Philadelphia Warriors in 1946, and won the first BAA championship title in the same year under coach Edward Gottlieb.  The Warriors later joined the NBA at its foundation in 1949.  The Warriors' record was 26–42 in their first NBA season and lost in the first round of the playoffs to the Syracuse Nationals.  Franklin Mieuli and the Diners Club put together a group of 40 local investors to move the Warriors to San Francisco before the 1962–63 NBA season, with Mieuli eventually buying all the shares of the franchise to keep the team from collapsing and to keep it in the area.  The team became the Golden State Warriors and moved to Oakland before the 1971–72 NBA season.

List of Golden State Warriors seasons: The Golden State Warriors are an American professional basketball team based in Oakland, California.  The franchise has also been based in Philadelphia, Pennsylvania, San Francisco and San Jose, California (during a renovation of their home arena) during its existence.  The team is a member of the Pacific Division of the Western Conference in the National Basketball Association (NBA).  The Warriors initially joined the Basketball Association of America (BAA) as the Philadelphia Warriors in 1946, and won the first BAA championship title in the same year under coach Edward Gottlieb.  The Warriors later joined the NBA at its foundation in 1949.  The Warriors' record was 26–42 in their first NBA season, and they lost in the first round of the playoffs to the Syracuse Nationals.  Franklin Mieuli and the Diners Club put together a group of 40 local investors to move the Warriors to San Francisco before the 1962–63 NBA season, with Mieuli eventually buying all the shares of the franchise to keep the team from collapsing and to keep it in the area.  After playing several home games in Oakland from 1967 onward, the team moved to Oakland full-time for the 1971–72 NBA season and changed their name to the Golden State Warriors.

Klay Thompson: Klay Alexander Thompson (born February 8, 1990) is an American professional basketball player for the Golden State Warriors of the National Basketball Association (NBA).  The son of former NBA player Mychal Thompson, he played college basketball for three seasons at Washington State University, where he was a two-time first-team all-conference selection in the Pac-10.  Thompson was selected in the first round of the 2011 NBA draft by Golden State with the 11th overall pick.  In 2014, he and teammate Stephen Curry set a then NBA record with 484 combined three-pointers in a season, as the pair were given the nickname the "Splash Brothers".  Thompson is a three-time NBA All-Star and a two-time All-NBA Third Team honoree.  In 2015, he helped lead the Warriors to their first NBA Championship since 1975.  Thompson helped the Warriors return to the NBA Finals for a third straight year in 2017, winning his second NBA Championship.

Hank McDowell: Hank Leigh McDowell (born November 13, 1959) is a retired American professional basketball player.  Born in Memphis, Tennessee, he was a 6'9" (205 cm) 210 lb (95 kg) forward and he played collegiately at Memphis State University (now called the University of Memphis).  He played in the National Basketball Association (NBA) from 1981 to 1987.  He was originally selected as the tenth pick in the 5th round of the 1981 NBA draft by the Golden State Warriors.  During his six-year NBA career he played with the Golden State Warriors, Portland Trail Blazers, San Diego Clippers, Houston Rockets and Milwaukee Bucks.

2016–17 Oklahoma City Thunder season: The 2016–17 Oklahoma City Thunder season was the 9th season of the franchise in Oklahoma City and the 51st in the National Basketball Association (NBA).  On the 4th of July, Kevin Durant announced he would leave the Thunder and sign with the Golden State Warriors.  On the April 9, Russell Westbrook broke the record of Oscar Robertson of most triple-doubles in a season with 42.  Westbrook would go on to be named the League's MVP in June.

Matt Barnes: Matt Kelly Barnes (born March 9, 1980) is an American professional basketball player who last played for the Golden State Warriors of the National Basketball Association (NBA).  Barnes was drafted in the second round of the 2002 NBA draft by the Memphis Grizzlies.  He won an NBA championship with the Golden State Warriors in 2017.

Supporting paragraphs: 2016–17 Oklahoma City Thunder season Kevin Durant
Answer: September 29, 1988