Bingo!
QUALITY OF CONTACT!!! Like golf, hitting the ball on the sweetspot of the club gets you the best results. Shane hits the headball nearly perfect every time. I have a friend that breaks WAY harder than I do, but has ZERO control over the cueball and he hits the headball in a different spot everytime....his results are as inconsistent as his contact. The correlation is obvious.
think Shane hitting that BREAKRAK thing a gazillion times has anything to do with his consistency??
Absolutely! I'm really glad Shane has brought such a big break to the game without throwing his whole body at the cue ball. Hopefully this will inspire young, developing players to adopt his style (No knock against the pros who have developed great breaks the other way, though).
One thing I've noticed about many pros is that they actually move way LESS before and during the break stroke than it appears. A lot of the movement occurs after contact to dissipate speed/power of the cue going forward.
Back to "Quality of Contact": This is BIG. Golf was used as an example, but it applies in many sports. You can hit more powerful shots in tennis or longer hits in baseball if you hit the ball CLEANLY, rather than faster or harder. Power/speed are important as well, but a clean hit that transfers all the inertia from the cue to the cue ball and then to the rack is the most important factor.
For those who have the break speed app on their smartphone, watch the break speed and compare to how loud the impact is or how "hard" the break seemed compared to others. I see breaks hit at 19 MPH that look monsterous and some hit 24 MPH that seem like a weak break. The difference is a cleanly hit cue ball and a really full hit on the one.
Timing is the other big factor, particularly with Shane. His tip is accelerating all the way through the cue ball, and he's contacting it at the point in his stroke where the cue is moving fastest. Timing is hard to teach; some people just have it innately. My 12-year old son has been studying Shane's break and trying to copy it for 18 months or so (he was still 11 when this video was taken):
http://www.youtube.com/watch?v=zbHyydXc7l0