1
whether or not the pitching arm is set vertical right before the point of max effort.
'Vertical' meaning up-and-down? Relative to the ground? ... um...
Lot of neat stuff at The Pitching Mechanic, although don't know why O'Leary analyzes the so-called "rushing" phenomenon the way he does...
Also not sure where at The Pitching Mechanic we get the idea of 'set vertical' ... you could 'splain the "set vertical" phrase, will respond...