J.R. Smith
Two things about J.R. Smith are obvious to everyone who knows anything about him: J.R. loves to shoot, and J.R. hates to wear shirts. While the latter fact is not important to his ability to be a good teammate, the former is.
Once, while in a playoff game with the Denver Nuggets, head coach George Karl drew up a play that was designed to end up with the ball in the hands of Allen Iverson or Carmelo Anthony. Instead, J.R. held the ball, took the shot, and the Nuggets lost.
Where Are They Now: Smith once again proved his on-court obtuseness in Game 1 of the 2018 NBA Finals, when Smith tried to run out the clock, which had 4.7 seconds left, not realizing that the game was tied. He initially admitted not knowing the score of the game, leading to a press conference where reporters badgered LeBron James about his teammates lack of on-court awareness. James would famously respond by storming out of that press conference.