The 75 greatest players in NBA history, ranked by Player Efficiency Rating (PER)

14.    Tim Duncan-24.22

NBA legend and San Antonio Spurs icon Tim Duncan ranks as one of the most productive players in league history so it's not surprising to see him rate high in all-time PER. Duncan was known for his consistency, averaging at least 20 points, 10 rebounds, and 2 blocks per game over the first eight seasons of his legendary career.

Actually, over the course of his 19-season career, Duncan was just one of two players, the other being Kareem Abdul-Jabbar, to amass more than 26,000 points, 15,000 rebounds, 3,000 blocks and 3,000 assists. Factor in that he was very efficient as a scorer thanks to his mastery as a low-post threat and as a mid-range shooter and it is clear why Duncan ranks so high in PER.

PER also takes into account the pace of play and during his prime, Duncan played in one of the slower eras in NBA history and for one of the slower teams. On a per-possession basis, he put up truly outrageous numbers. That also explains why he cracks the top 15 in PER ahead of players who may have put up more gaudy counting stats, which helps give credibility to the stat as a valuable metric.