To this day one of the best, most entertaining dunkers I have ever seen was a reserve guard at St. John's in the 60's named Mike Rowland; No more than about 6-3, but could do all kinds of things dunking the ball back in the day when you had to get in all the pre game dunks before the officials came out. Rowland was incredible. Well worth getting to the arena early; Which I did anyway to watch the freshmen games. Yes, back before freshmen were eligible. There were two guys from my neighborhood who began their careers at St. John's in back to back years. Ironically, there was freshman at St. John's in 1966-67, Bob Staak who ended up transferring to UConn; Excellent spot up shooter.
I have a theory about why white guys do not maximize their jumping potential and am convinced that every good white athlete is fully capable of outstanding leaping ability.