Elrod of RealGM has been advocating what he calls "the Iron Law" for quite a while. Here's what it states:
The Iron Law is simply this: to win an NBA championship the best player on a team has to be one of the five best players in the league and one of the two dozen or so best players of all time. The NBA is not a democracy. It is a league ruled by superstars. 38 of the past 51 NBA titles were won by teams led by nine players: Russell, Chamberlain, Abdul-Jabbar, Magic, Bird, Jordan, Olajuwon, Duncan and Shaq.
Three more were won by teams led by other top-20 all-time players like Rick Barry, Moses Malone and Julius Erving. Bill Walton was en route to a certain all-time top 15 status until injuries derailed him, and that is another title team. That makes over 80 percent won by teams led by this caliber of player. No other team sport has anything close to domination of its championships by teams led by the league’s single best players.
Read his analysis of what this means to Kevin Garnett and the Celtics here.