From the "Greatest Sports Legends" Dvd's nearly all the 8mm b/w stock footage from the early 60's players showcased within the documentary is either precisely
20% slower than real-time, or precisely
4% slower than real-time. In fact I can only reasonably conclude that all of it is either played back at 4% or 20% slower than real time (I can not prove this however, because a shot clock is only visible in a little over half the clips... but all the clips appear come from the same central stock recorded and played back with the same equipment... so it should all be the same). I've figured this out by analyzing all the clips with shot clocks which are visible in the Elgin Baylor and Bob Pettit player mixes I worked on or am currently working on (about half of all the clips have a shot clock visible). I believe that early 60's b/w footage like this which is/was used as stock in many of the mixes and documentaries of the past 5-10 years, as well as the later 60's to early 70's use of true slow-motion photography are the combined reasons why people who never saw those athletes play have come to believe those players were 'slow'. Bob Pettit looks remarkably quick and agile with adjusted footage. And inversely, looks remarkably slow with unadjusted footage.
BTW, I'd be more than happy to upload a screen capture video that demonstrates this if anyone understandably won't just take my word for it. 20% speed difference is enough that an untrained eye (especially with a bias or tendency to believe the 1950's and 60's were played by sluggish athletes) could be fooled into thinking it is normal playback speed and that the athletes are just 'slow'. Only someone analyzing the physics of the ball might suspect otherwise. And only someone with the software to analyze the footage frame by frame could come up with the precise percentage that the playback speed needs adjusted too to be corrected.
Inb4 'STOP SPEEDING UP FOOTAGE'!