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

54.    Alonzo Mourning, 21.24

Former NBA star Alonzo Mourning was known as one of the best two-way big men of his era. That is really saying something considering he played in the 1990s with the likes of Shaquille O'Neal, David Robinson, Hakeem Olajuwon, and Patrick Ewing.

Mourning was a stout defender who not only won Defensive Player of the Year back-to-back seasons but averaged more than 3 blocks per game five times, including leading the league twice in that category. Factor in that he averaged at least 20 points per game six times and has a high career true shooting percentage and it is understandable why Mourning makes an appearance on this list.

Considering how his career was nearly derailed by kidney disease and the need for a kidney transplant, Mourning wasn't able to put up the same cumulative numbers as his contemporaries. That being said, PER does show that he was a very productive player during his prime, which includes his time with the Charlotte Hornets and his first stint with the Miami Heat.

No one is going to argue that he is actually a top 55 player all-time but had he not gone through those health issues, he might have been considered to be one.