Without knowing it, Chicago Cubs rookie slugger Javier Baez pays homage to Isaac Newton's Third Law of Motion with each swing. He takes big giant cuts and hits big giant homers. The problem is, the equal and opposite reactions to the mechanics that generate all that power render the other parts of his swing wildly unstable.
In Baez's case, it's his massive "hammer." A player's hammer position is how he loads his hands at the start of his swing, and as with any athletic movement—punching, kicking, throwing—you must go backward to create energy going forward. (For this case study, we are going to ignore Baez's lower half.) The hand load is intended to create bat whip, like a twisted towel used to crack unsuspecting freshmen in high school locker …