22. Jon Gray (Rockies Career WAR 11)
Jon has only been pitching in the big leagues for 5 seasons now. But he is already in the top-7 for every major pitching statistic from wins to Career Pitcher WAR.
That is insane production in such a short time frame. So many have wanted to right off Jon already in his young career like so many other homegrown pitchers in their past he had his struggles. Though he bounced back in a big way in 2019 posting a career year winning 12 games, striking out 150 in 150 IP with an ERA of 3.84 on a very bad team with a historically bad bullpen.
With a better roster, he pitched well enough that he would likely have garnered some Cy Young votes. Jon showed again why he was the 3rd overall pick in the 2013 draft.