The Yankees’ faith in Domingo German has been rewarded

The Yankees’ rotation depth was a major cause of worry for fans prior to the season. Those fears were only stoked when Luis Severino’s trip to the injured list was originally announced just before Opening Day.

While Severino’s injury situation remains worrisome, the on-field rotation has remained surprisingly potent. A large part of that can be attributed to the emergence of a certain pitcher, who was previously considered to be depth, but is now putting up Severino-esque numbers across the board. That arm is none other than — you guessed it — Domingo German.

The dominance that German has exhibited over his first eight starts is absolutely remarkable. As a starter, the right-hander owns a 2.61 ERA and 3.12 FIP, and opponents are slashing just .186/.249/.305 against him. The die-hard Severino fans among us might take exception to my usage of the adjective “Sevy-esque”, as German does fall just a bit short of the injured ace in terms of strikeouts, walks and groundball rate. However, such fans would be missing the larger point: German starts are beginning to feel like automatic gems, just like Severino’s early last year.

The parallels between the two pitchers don’t end there. Prior to his 2017 breakout, Severino was absolutely dismal in 2016, posting a 5.83 ERA amid being relegated to long reliever duties mid-season. Likewise, German’s 2018, while encouraging at the beginning, eventually saw him post a horrendous 5.57 ERA. Both arms were obviously talented, but both struggled to reach their potential. For Severino, the key to his breakout was fastball location and the introduction of his slider. What has been the factor in German’s case?

Is it location, like Severino’s fastball command? The data suggests otherwise, as German hasn’t located his fastball nor his curveball — his bread-and-butter combo — any differently than last year.

Is it a new pitch, like Severino’s changeup? It is not, as German’s arsenal hasn’t changed. He has three pitches: his aforementioned fastball-curveball combo, and a high-80s changeup. He’s thrown each about as often as he did in his previous campaign.

Is it improved stuff? No again, as German’s fastball velocity and curveball movement have been essentially the same — that is, elite — in both 2018 and 2019.

The truth is, German is largely the same pitcher he was last year. It’s not him that’s changed, at least in terms of skill; it’s just his results. German was the recipient of bad luck, or more specifically poor timing, in 2018, which inflated his ERA. In 2019, the tables have turned.

Even during German’s sub-par 2018, he showed a high ceiling. We not only have anecdotal evidence to show that, but also statistics. He actually struck out hitters at a higher clip (26.2% as a starter) than this year, proving that stuff wasn’t a problem.

What plagued German in 2018, as Jake showed last year, was allowing hits at inopportune times, especially with men on base. With the bases empty, opposing batters hit .237/.302/.448 off of German last year. With men on base, that line slid to .248/.337/.468. It didn’t help that he was allowing homers by the dozen, with a 1.71 HR/9 and a 16.25% HR/FB. Unsurprisingly, German allowed a ton of baserunners to reach home, as his 2018 strand rate of just 60.9% was well below the league average of 72.6%.

This year, German in excelling in those same situations. He’s bearing down extremely well with runners on base, holding hitters to a .188/.254/.266 line. His strand rate is more than 15 points higher, at 75.5%. It helps that his BABIP has been extremely low, currently at just a .230 clip. Meanwhile, his HR/FB has improved to just 7.8%. These numbers, and not changes in German’s fundamental skill level, represent the difference between his 2018 and 2019.

German’s low BABIP aside, it may be crude to call this turnaround “luck”. I imagine that many fans would rather attribute his breakout to an improvement in German’s “clutch-ness”. That may indeed be the case; maybe emotional maturity or mental fortification was the key. However, baseball analytics has yet to find a way to quantify such factors and integrate them into predictive models.

What analytics have shown is that strand rates tend to bounce around from year to year, and generally fall close to 73 percent for any given pitcher over his whole career. Same for HR/FB, which is a bit more skill-based than strand rate, but is still subject to yearly fluctuation and needs a very large sample to be meaningful. Analytics have also shown us that splits like runners on base, while sometimes striking, generally have little to no year-to-year predictive value. When looking at a pitcher like 2018 Domingo German, analytics tells us that his ERA should be taken with a grain of salt, and to bet on better days as his splits and strand rate should normalize in the future. That’s just what the Yankees did, and the return has been nothing short of magnificent.

Baseball is a cruel game. Even pitchers who do most things right — getting strikeouts, reining in walks, and not allowing hits — can be burned by things like wind-aided, wall-scraping homers, sub-par defense, or uncooperative umpiring. However, baseball also has a way of rewarding players who persevere and keep doing things right, as well as the teams who keep their faith in such players. That’s certainly been the case for German and the Yankees.