After hearing Shaq talk about Derrick Williams Jeff Green and Rudy Gay has some of the more underachieving players in the league who else could/should be on this list. I think of guys like JR Smith who can dribble drive and shoot he just doesn't have the IQ and thinks a 3 with 20 seconds on the shot clock is a good shot for him to take. But physically and athletically he should have been the 2nd best two guard in the league after Kobe in the mid 2000's. He showed flashes and the year he won 6th man of the year many thought he had turned the corner but he is still the same player after all these years.