Based upon my personal beliefs, you need to evaluate all-time great players based upon regular season performance and playoff performance, dominance, honors and recognitions, and titles won. In connection with titles won, you need to evaluate the importance of that particular player to his team - did he lead them to the title? Was he THE star? Were they a title team without him?
The strongest case for Jordan as the best player of all-time is not his MVPs or his all-NBAs or his freakish statistics offensively and defensively. It is simply this - his team dominated and won three titles while he was their star, and within 1 1/2 seasons of him leaving, they were slumping toward .500. He then returned and within 1 year they were champions again....3 more times. There has never been anyone else who can claim that.
Why is Kevin Garnett historically underrated? Because looks at the Wolves - historically bad before KG and historically bad after KG. His presence on the team, with virtually no help, was a +20 wins per year.
Anyway, then we turn to titles. Is Bob Cousy a better player than Charles Barkley? I'd say no. But he has more titles. Is John Havlicek a better player than Karl Malone? Doubtful - but he has more titles. People tend to perceive you as a better player if you win more titles. Was Robert Horry a better player than Alex English? No, but you will find someone willing to argue that point.
The greatest players in the history of the game, in my opinion, are, in order:
Should Duncan post title #5, he has a decent argument that he should be up above everyone but Kareem and Jordan. Imagine that - the 3rd best player of all-time.
Should LeBron win, it gives him a second title. I think he could argue that he should move ahead of
Shaq and Bird and into 8th. (His regular season stats are better than either man's; and he certainly has been a far more consistent defender than either Bird or Shaq were; or, in Shaq's case, chose to be.)
A loss for Duncan leaves him where he is at (#6) and also moves LeBron closer to him on the list - plus LeBron at #8 has a lot more years to play and will have established the upper hand on Duncan, he would be in a good position to pass Duncan.
As a couple final notes - no, Kobe is not on my list. I do not feel that either his one measly MVP or his three titles riding Shaq's coat tails justifies his inclusion on the list. His career advanced stats simply do not match up to those of the great players on the list. He has an argument for 11th place, if you could place him ahead of Karl Malone, Oscar and Jerry West in good conscience. Bill Russell is the hardest guy to place on the list. You could leave him off completely (he shot 43% from the floor and 60% from the line in playoff games - he basically played one end of the floor). Or you could put him at #1 (Celts were unbeatable when he played, immediately not as good before or after). I think placing him at #7 is a fair compromise. Mikan, I believe, is historically underrated. His dominance in the years he played was Jordanesque.