While I haven't read a word of the responses (yet). The question triggers a favorite memory of just that nature.
I was spectator at a weekend 9 ball tournament at the Hunt and Fish in Portland.er uh sub burb maybe. (Think it was Beaverton)
The 7 foot tables were stymie ing the power breakers. The best in the Northwest had power breaks. None could solve the situation, then along came Don Wirtiman. The older Elmer Fud looking guy. He broke about 3/4 speed (top speed for the old guy wasn't that fast either

) and the balls just found the pockets. The big table big breakers got a bar box lesson that day.
The velocity and rotation of the balls striking the rails changes the rebound angle significantly.