Sample size, sample size, sample size.... ad nauseum.
Anyone that thinks two tippity top pros aren't continually going near hill/hill in an alternate break format, need to remove their noses from their calculators. ...
It turns out that winner breaks and alternate breaks give the same chance for the better player to win the match. It has nothing to do with observation or sample size, it is pure probability theory.
This assumes that psychology doesn't play a part in the outcome. I think it's better to keep psychology out of it because you can argue on both sides whether one format helps or hurts a particular player based on his attitude/mindset.
That the break format doesn't affect match-win probabilities is quite an amazing result.