Video: J.R. Smith gets up for the slam after a downerEric FreemanJanuary 27, 2011On Tuesday night, J.R. Smith(notes) was benched for the entirety of the Nuggets' game against the Raptors after arriving late to shootaround. It was a low point for the erratic guard, and he tweeted his anger in the wake of the benching.Then he came out for Wednesday night's game against the Pistons and had the best dunk of any player on the night. It was a classic Smith moment, a sequence of dominance at a time when he seemed to be at his childish worst. It's a massive understatement to call Smith inconsistent -- instead, he vacillates wildly between two poles of basketball usefulness with startling regularity.The dunk here is pretty stellar. Smith gets the feed from Ty Lawson(notes) -- who drew three defenders -- and rises up at an odd angle. He realizes this quickly, and adjusts his arm to jam it in while seemingly as uncomfortable as you can be in mid-air. No matter, though, because when J.R. is at his best he's able to change direction on the fly and generally do things you see from a handful of other shooting guards in the league.Those glimpses of excellence can be extremely frustrating; if he can do this occasionally, why can't he keep his head on straight and become a star. The answer is unclear, but after nearly seven seasons these abrupt shifts from greatness to stupidity are quite plainly facts of Smith's style and personality rather than unfortunate displays of immaturity that can be turned around with age and experience.Lament it if you want, but realize that in doing so you're missing out on appreciating someone who provides more moments of unbridled joy than the majority of the league's consistently productive players. J.R. Smith probably won't win your team a championship, but he sure makes things watchable. That's a worthwhile skill in itself.