I'd say fifty to a hundred, probably closer to the higher number. Just about every city has one or two guys that can play even with the top players. You may not hear as much about them but they are out there laying in wait.
Even on the various regional tours, there are always eight to ten pro level players competing. It's not easy for even a top player to win one of these events. Take for example last weeks Swanee tourney with Bustamante and Gallego both competing. You would think one of them would win, but Brian Parks demolished Francisco and left him in fourth place. In the Texas Open the same weekend Manny Chau took it down and poor little Dennis Orcullo also finished fourth.
On second thought, my estimate is probably still to low. Taking the entire country into consideration, there may be a few hundred capable of winning matches against top ranked pros. There's a lot of good pool players in the US, more than in any other country by far. Problem is that most of them are not interested in traveling the world to make a living. They either have jobs, families or other reasons for staying close to home. Maybe they just like that home cooking! Beating the roads playing pool is a hard way to make an easy living.
