In basketball, a higher index helps with defense, especially in contesting shots and intercepting passes . It also helps with rebounding, and with dribbling or passing under pressure. Finally, it directly helps shooting under pressure. David Epstein in his book "The Sports Gene" devoted a chapter to "The Vitruvian NBA Player" and therein noted "The average arm-span-to-height ratio ape index of an NBA player is 1.063." Having an ape index of less than 1 is very rare among NBA players; only two players in the NBA 2010–11 season had one.