OK. I can sum it up simply:
The best players make the best decisions most often. Period.
Now, which of those decisions are most important can be debated.
Having the most chips in a game DOES NOT make you the best player. I've seen some of the worst players have some lucky runs and make themselves seem like great players. Then I've seen some great players go on bad runs due to luck, even though they made good decisions.
On a personal note, there are some players here on CC that have had some nice winning runs who I wouldn't consider great players because I've seen them make too many bad decisions. But on the flip side, I've also seen some players here on CC who aren't viewed as big winners but always seem to make good decisions when I play them and I consider them great players.
Anyway. I think you have to watch a player actually play (observe or actually play against them) to decide whether or not they are really good. Posted results here and there don't always tell the truth.