20. Most Rebounds in an NBA Game (55)
Set By: Wilt Chamberlain
The most rebounds in a single game since the 1985-86 season is 35 by Charles Oakley. To approach Chamberlain's 55, you'd need incredible skill (which many players obviously have) combined with a size disparity that nobody can overcome and rules that create lots of chances for boards (that, not so much). Chamberlain played in an era where practically nobody was even in the same category as him physically, with Bill Russell, Walt Bellamy, and Bob Pettit being the lone exceptions. Each team also had significantly more possessions per game, on average, which thus created many more rebounding opportunities. With so many guys of roughly similar stature and defense actually being an important part of a game now, there is no way anyone can touch this record.