I think most of the things that have been mentioned here are true, at least to some degree. I think the best players on the planet do all things, related to playing pool, at least a little bit better than those of us who are not the best players on the planet.
I think there are 2 primary reasons for this, Skill and Consistency.
Skill comes from eye hand coordination, physical aptitude etc. Whatever it is that lets one get better faster than another.
Consistency, probably just another part of skill, is something often overlooked. I once read an article about golf where they measured the foot position of pro golfers for many many shots. The pattern would amaze you at how often they put their feet in almost the exact same place. When they did the same thing for the amateurs, it was a different story. I this applies to pool also. The Pros come to the table and assume the almost exact same stance each time. Their bridge length is the same, their feet are the same, they bend over the same, all of it. Let's face it, this makes being consistent allot easier!
I know that when I watch John Schmidt or any of the other top ranked pros, the balls seem to go into the very center of the pocket much more often than with amateur players. This is subtle, but amazing!
They really do play ALLOT better!
Royce Bunnell
www.obcues.com