I no that Oscar Dominguez plays on 4" pockets in his homeroom. I also heard that for a few years he was using a cue with a very small dia. I think the guy that told me said it was 10 or 11 mm. I have a 10 mm. snooker cue and tried it. At first I would be putting spin on the QB when I wanted to hit center ball, but after awhile I was spilting the pockets on long straight in shots. I think it's a great way to practice center ball. It made me bear down more and my pocketing has got a lot better from it. Johnnyt