It works for trees.
Nah, just playing. The thing is, winning is a sign of greatness. Truly great players are able to take over games and flat-out refuse to let their teams lose. That is what set players like Michael Jordan, Magic Johnson, Larry Bird, Bill Russell, Wilt Chamberlain etc. apart.
There are other variables for sure, and other ways of evaluating a player's greatness. To really prove that you are the best player in the league though, you need to prove that you can reach the top level of the team game by winning a championship.
The point of playing a basketball game is to win, so players are evaluated not by their ability at any of the individual components of a basketball game, but how well they can work towards achieving that end. That's why rings are such a big deal.
In my mind, Lebron is best player in the NBA, talent wise. He makes like 3 amazing plays a game and can just dominate at almost any time.Until he wins a championship though, Lebron cannot claim that title from Kobe.
Kobe just flat out knows how to win. If you watched last night's Lakers-Suns game, you saw Kobe just take over. Kobe refused to let the Laker's lose, and so he just went off on the suns. Kobe Bryant still has an edge though on Lebron, in that Kobe is capable of taking a game over to the extent that it is literally impossible to beat him.
Until Lebron does that, Kobe will hold on to the title of the Best Player in the NBA. I think Dwayne Wade is 2nd personally, then Lebron and then Durant. Lebron and Durant just haven't shown that they can take over like Dwayne Wade and Kobe have.