Does baseball have a supply-and-demand issue when it comes to relief pitching? If so, what's behind it?
You wouldn't think this would be a possibility. For the past few years, as more and more innings have shifted from starting pitchers to relievers, we've heard about waves and waves of thunder-throwing young pitchers who have rendered the old models of pitching staff construction as obsolete as the rotary phone.
Yet there is a finite supply of everything in this corporeal existence of ours, and the consumption habits of humans being what they are, you had to figure we'd rub up against the outer limits of fungible -- but effective -- relief pitching. But these trends are so new and have accelerated so quickly that if the supposition presented in the first sentence above were to have some substance, it would be pretty surprising.
It's early. Every analysis piece with an April publish date must wear that caveat around its neck. Through Wednesday, we had played just under 15 percent of the 2019 season. That's right! We get to do this all 6.67 more times. Everything suggested here could be rubbed out by reality's eraser.
Nevertheless, here are some numbers comparing starting pitchers to relief pitchers in each of the past 10 seasons, with each season measured through the end of April.