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

56.    Blake Griffin-21.03

Former number one overall pick Blake Griffin has yet to officially retire but at 35, his career is all but over. Griffin was one of the most hyped players when he was drafted in 2009 and put together one of the best rookie seasons of the last 25 years, posting 22.5 points, 12.1 rebounds, and 3.8 assists per game with a PER of 21.9. 

That proved to be par for the course, with Griffin having a PER over 20 over each of his first seven seasons and eight overall. His elite athleticism paired perfectly with that of Chris Paul's playmaking and formed "Lob City," with Griffin getting plenty of his great shots. 

That helped him become an efficient 20-point per game scorer during his prime. After being traded from the LA Clippers to the Detroit Pistons, Griffin remade his game, playing more with the ball in his hands and emerging as a high-volume 3-point shooter. 

That helped to prolong his career, and after injuries had quickly drained him of his leaping ability, he spent the final four seasons of his career as a role player, though his stellar production helped him rank in the top 60 in all-time PER.