OK, I have a few minutes to spare so here's an explanation of the difference in the rails used on the TAR table. When TAR first wanted to put a set of rails on the TAR table, Diamond at the time didn't make rails with 4 1/8" pocket opening, so because Fatboy's 9ft Diamond ProAm was in storage at the BCA warehouse, they borrowed the rails off his table and put them on the TAR table to start the beginning of the TAR table with tighter pockets. Shane and Alex played on this set of rails on the TAR table, and they both had high package runs, notably Shane with two 6 packs and one 7 pack. The rails were replaced after that with rails Diamond manufactured at the factory with the same pocket openings being 4 1/8".
Now comes the difference between Fatboy's rails and Diamond's. Though both sets of rails have the same pocket opening at the jaws of the corner pockets of 4 1/8" and the same down angle being 15 degrees, the difference between the two sets is in the miter angles. Diamond built there rails with 141 miter angles, while I built Fatboy's using 140 miter angles. Now, that may not seem like much of a change, but there's a few side effects of that change that do make a difference in how the balls act when being played in the pockets. First of all, there's a 1/16" of an inch change per degree of angle over the distance from the back of the pocket to the point of the pocket cushion...per side. So, that means the at the back of the throat in the corner pockets on Fatboy's rails...it's an 1/8" wider than the Diamond built rails. Second, the one degree difference in miter angle means the balls when coming into contact with the pocket facing going into the pocket are deflected a little deeper into the throat of the pocket than on the Diamond built rails, which translates into less of a ball rattle in the jaws of the pocket, resulting in more balls going in, instead of still sitting in the jaws of the pocket, meaning balls having a little better chance of going in if shot with good pocket speed.
After the Shane and Alex TAR match, the rails were switched out for the Diamond built rails.
Now, as far as Ernesto built pockets on a GC being 4". Think about this for a moment, at 4" pocket openings, there's virtually no pocket shelf for a ball to sit on, meaning a ball can't rattle to a stop in the jaws of the pocket, second...the miter angles are at 135 degrees, or very close to that, which means the throat of the pocket is almost the same as the pocket mouth opening, so balls that are hit into the pocket facings are deflected clear to the back of the pocket, with almost no chance of being bounced across to the other side of the pocket, meaning the pocket is a small target, but the hallway the ball has to pass through to drop in the pocket is huge which means if you just get past the point to point opening of the corner pocket...the ball is GONE!