The best break is the one that gets you a shot on the one most often. Current WNT break rules aside, since they are a different animal, if you squat the cue ball on every break but end up with no shot most of the time, then it’s not a great break. Which is why over the years we’ve seen top players draw the cue ball two rail back and up table because it was reliably getting them a shot into the side pocket. They adjust the cue ball control and hit on the one to control both balls depending on the conditions of the table and rack.