"training concentration"

[Cameron Smith]

Here's a good video of Nick Faldo discussing concentration. Although he is speaking in the context of golf, it most certainly applies to pool as well.

http://www.youtube.com/watch?v=foLHqBKiyXI

I know that when I am playing well, I never consider missing a shot. Wheras when I am frusterated and playing poorly, I'm constantly telling myself "don't screw up".