I guess I have to answer this question at least once a decade. FATS COULD PLAY! He did play a ball under the top players in One Pocket, but no one was rushing out to match up with him. If you locked Fats in a room with all the top players, he would come out with all the money! I hope that makes sense to everyone.
I did see Fats gamble three times and all with top players. He won all three times, including beating Richie out of twenty five grand, getting a ball (in the 60's). By the way, Fats finished second to Johnny Vevis in the first Johnston City tourney, with fourteen of the best One Pocket players entered. It may have been the only tournament he ever played in.
I never saw anyone who could shoot one very tricky One Pocket bank better than Fats. If the object ball is between the first and second diamond (on or near the rail) and the cue ball is down near his pocket, he could bank that ball back down into his pocket with amazing accuracy, and send the cue ball three rails for position. He made that shot look like a hanger.
Mosconi didn't like Fats because he got hustled by him once. Fats wanted to play Banks and Willie wanted to play Straight Pool. So Fats thought up a new game, Bank Every Other Ball. Guess how that game turned out? Fats told me that Willie emptied out the cash register in his dad's pool room. They were never too friendly after that.