Well, there's a little more to the pockets on a table besides just making them 4 1/2" wide at the mouth that determines how they play. Pocket angles have a big effect on how a pocket reject balls or accepts them and at what speed. Pocket facings play a major role as well. Then yes, the pocket slate shelf has it's effects too. I can take 2 matching Diamond 9ft ProAms with the exact same 4 1/2" pocket openings and make them play very differently as in one harder to pocket balls in than the other, so I guess what I'm saying, is that there's more to a pocket than just the opening.