Basketball has always been obsessed with height, but at some point (Bill Simmons suggests when Scottie Pippen was drafted by the Chicago Bulls in 1987) the NBA started to pay attention to wingspan — the distance from fingertip to fingertip with arms stretched out sideways. Rock climbers call this the Ape Index: when reaching for a handhold, it’s useful to be a nimble little acrobat but with long arms.
The average man has a wingspan roughly equal to his height, but the average NBA player has a wingspan 4 inches wider than his height.
The largest relative wingspan listed for a white star was 1980s Boston Celtic Kevin McHale, who was 6’10” and had a 7’5″ wingspan. (These are not surprising to any 1980s NBA fan.)
The great Bill Walton says that nobody ever measured his wingspan when he was at UCLA in the early 1970s. I can, however, remember in 1971-1972 the L.A. Laker announcer Chick Hearn explaining that Laker legend Jerry West was the same height as him, 6’2″, but while Chick had his sports coats made with a 35″ sleeve, Jerry had his made with a 38″ sleeve, which is why he had so many steals and even blocks. (I’m 6’4″ and wear about a 34″ sleeve).
The downside of a long wingspan is that it’s harder to precisely control shots. Pippen, for example, with his 7″ wider wingspan than height, was awfully good at everything on the basketball court except shooting. Pippen’s senior partner Michael Jordan was listed at 6’6″ and 6’11” wingspan, suggesting that +5″ might be optimal.
Shorter-armed players in the NBA tend to be better shooters. Stephen Curry has arms only 0.5″ wider than his height.
Most of the top wingspan players were not great offensive players, even Wilt Chamberlain (7’1″ height and 7’8″ wingspan). Late in his career, Bill Sharman talked Wilt into not shooting so much and he proved to be an extraordinary defensive force.
My guess is that in the future, the NBA will refine its wingspan measurement into arm length vs. shoulder width, with the shoulder width being considered an all-around good, but arm length having pros and cons. Walton, for example, had hugely wide shoulders, as I observed following him down Rush Street in Chicago in 1999, which I suspect is why people didn’t talk as much about how long his arms were. McHale appeared to have fairly narrow shoulders, although, keep in mind, that’s relative to all the Specimens in the NBA like Patrick Ewing and Karl Malone.