Naji, this is just for your eyes and I'd appreciate it if you don't tell the others. I have a good collection of one-pocket matches on DVDs - all good players and no bums (pool-wise). Several years ago I set out to see whether the break was as good as most of the guys say it is. By the time I had clocked 115 breaks in these matches, I found that the breaker had won 58 times and lost 57 times. I'm not trying to say that this ratio would continue throughout, but my count was legitimate. I think that the break is a greater advantage for most of us than it is for the best players, probably because they are able to deliver better responses to the break than we can.
I don't think I saw a single scratch on the break, but I believe there were at least two or three matches in which the breaker did not win a single game.
I guess this proves nothing, but it's information, and that is always good. And remember - don't tell the other guys. They would be horrified.