I have studied, and pondered, baseball for most of my life yet I continue to be just utterly baffled by the difference between the health of pitchers 40 years ago and today.
“They didn’t throw as hard.” They threw plenty hard; certainly Nolan Ryan did. “They didn’t snap off sliders and splitters like today’s young ‘uns do.” Tommy John surgery, it turns out, correlates more highly with fastball velocity than it does to use of the breaking pitch, and when you look at notable pitchers of past generations you see Randy Johnson snapping off wipe out sliders to go with his high-90s fastball, while throwing one out shy of 1,030 IP over 4 consecutive seasons.