The MVP Machine: How Baseball's New Nonconformists Are Using Data to Build Better Players

by Ben Lindbergh

Throwing a heavier ball—say, seven ounces—increases total force. When the pitching arm is cocked back to begin the throwing motion, in maximum external rotation or lay back, the ball feels heavier. The body adapts to manage the greater total force. But overload training could also be paired with underload training in a complementary, two-pronged approach that could improve total force and peak force. The underload ball enables the arm to move much faster, creating a higher peak force that ultimately determines throwing velocity. Strengthening the body with heavier balls and greater total forces allows it to take on greater peak forces. To many instructors, overload training seemed inherently dangerous. Still, some, like Cressey, had challenged that assumption as early as 2009, when he noted that the weight of a baseball (five ounces) was three times lighter than that of a football (fifteen ounces) but that quarterbacks suffer far fewer arm and shoulder injuries than pitchers, despite possibly throwing even more often. A typical set of weighted baseballs ranges from three to eleven ounces.