"Who's the best player?" means different things to different people. Some interpretations: - Their presence makes the biggest impact on their team in terms of increasing wins - Their presence makes the biggest impact on their team in terms of increasing probability of winning a championship - They have the greatest +/- impact, per possession, then any other player - They produce more "stats", per possession, then any other player - They have the most impressive array of skills and physical tools - They've "proven" themselves the most in recent years - and more ... I tend to like the first 3 interpretations more than the others, but they are the most difficult to quantify and also perhaps more context-dependent. Adjusted +/- tries to get at the third one, but there are different ways to calculate it and the results may be hit or miss. PER is nice as a relative easy to calculate summary rating of how the player is helping his team win, by the boxscore. But the limitations there are well-known.
Kobe isn't as young, and is trying to stretch his career as long as possible. He's not going to try to be as aggressive every possession, and work his hardest for the shots. A guy like Wade does that a lot, and Lebron doesn't do it all the time, but more often than Kobe. Paul also works his ass off. I think if Kobe was as aggressive as these guys he could put up PER probably close to as high as these guys, however playing hard increases the risk of injury. Look at a guy like Wade, he's had injury problems being as aggressive as he is. The Lakers have enough talent that they don't need Kobe to have a 30.0 PER to win 60+ games, Kobe can take what the offense gives him. The only problem is if there are injuries, and he still is in cruise-control (like Celtics-Lakers Final).
