Russell was the ultimate winner in the history of the NBA. He won a league title in all but two of his 13 seasons as a member of the Boston Celtics. Yes, the NBA consisted of just 8 to 14 teams during this period, so capturing championships was a statistically easier feat for a single franchise, but even that fact doesn’t minimize Russell’s historic accomplishments. The Celtics had played for 10 seasons before Russell joined the team, never once reaching a championship series in that time. But in his rookie year, Russell completely changed the franchise’s course and established the Celtics as the winningest team in the NBA. But he didn’t earn his place on this list though some sort of vague, ethereal “winningness.” Russell was one of the fiercest defenders of all time and he redefined the value of blocking shots, in addition to averaging an incredible 22.5 rebounds per game over his career.