21. Bill Russell (1962)
Team: Boston Celtics
Stats: 76 G, 45.2 MPG, 18.9 PPG, 23.6 RPG, 4.5 APG
Player Efficiency Rating: 19.4
How did Bill Russell beat out Wilt Chamberlain's 50 PPG and 25 RPG season and Oscar Robertson's triple-double average to become the 1962 MVP? Well, in addition to his across the board dominance on offense (a career high 18.9 points per game) and on the glass (23.6 per game), Russell was a complete game changer on defense. Although it didn't become a recorded stat until the 1973-74 season, blocks were what made Russell arguably the greatest defender in NBA history.
It's been reported that he would block, on average, at least four shots per game, and would alter countless others. As Russell himself said, the key wasn't to swat everything, but instead "to make your opponent believe that you might block every shot." He did that better than anyone else, leading the Celtics to the 1962 NBA title.