Kobe Bryant: men's basketball
Basketball was invented in 1891 by a Canadian - sports teacher James Naismith - but it is the United States that has always dominated the global sport.
Naismith was working at a US university when he was asked to create an indoor team sport as an 'athletic distraction' for students because of bad weather outside.
It was a demonstration sport at the 1904 Olympics and became a competitive men's event at the Berlin Games in 1936, which the US won - beating Canada in the final; the women's event started at the Montreal Games in 1976.
Professional players first played Olympic basketball at the 1992 Barcelona Games. The US won, with its first 'Dream Team' of NBA stars, including legendary Chicago Bulls star Michael Jordan; this victory was Jordan's second gold medal, after he won with the US as an amateur at the 1984 Games.
With 13 out of 16 Olympic titles, the US men's team are the reigning Olympic champions and will start as favourites. Their professional NBA stars have failed to win gold only once, at the 2004 Athens Games; they came third.
In London, the US men's team will feature some of the players who won gold in Beijing, such as Kobe Bryant, the Los Angeles Lakers guard, and the Miami Heat duo of forward LeBron James, and guard Dwyane Wade.
Twelve national teams in both men's and women's competitions will compete in London. The teams will be split into two groups of six.
The US men's team will play in Group A against Argentina - the 2008 bronze medallists - France, Tunisia and two nations yet to qualify. Britain are in Group B with Spain, the European champions and Olympic silver medallists in Beijing, Australia, Brazil, China and one nation yet to qualify.
In the women's event, the US - the defending Olympic champions and world number-ones - are in Group A with China, the Asian champions, Angola and three yet-to-qualify teams. Britain play in Group B with Australia, the world number-two team, Brazil, Russia, the reigning European champions, and two more teams still to qualify.
Teams in each group play each other, gaining two points for a win and one for a loss; the top four teams in each group go into the knock-out quarter-finals.
The 40-minute matches are split into four, 10-minute periods. The clock stops for each break and teams can call one-minute time-outs. Once in possession of the ball, teams have only 24 seconds to try to score a basket or they lose possession.
Fab Fact: The 288 players at the Games will use a total of 600 basketballs during the competition