For quite some time, the Mariners’ starting rotation has been bad. So very bad that Yovani Gallardo pitched 22 games for the Mariners last season. Just years ago, Felix Hernandez was regarded as the best starting pitcher in the American League, and Hisashi Iwakuma was considered by some to be one of the most underrated #2 starting pitchers in the MLB. The former threw a perfect game, while the latter tossed a no-hitter. Nowadays, Felix is more bad than good and Iwakuma’s shoulder might as well have fallen off.
Last year, Jerry Dipoto took a lot of heat for trading one of the Mariners’ top prospects in Tyler O’Neill for a soft-tossing lefty coming off of Tommy John surgery in Marco Gonzales. Interestingly, both were taken in the 2013 MLB draft. O’Neill was taken with the 85th overall pick (3rd round), while Gonzales was taken 19th overall (1st round). Ever the optimist, I thought there was some logic in trading a dice roll in Tyler O’Neill for something (theoretically) steadier in Marco Gonzales.
More recently, Gonzales has been making the trade look a lot more justifiable than it had been just a month ago. After pitching 4.2 innings with no earned runs against the Astros, Gonzales blanked the White Sox yesterday through six innings while striking out eight.
Gonzales was truly bad last year, or at best uninspiring. There’s a lot to unpack here, because it’s not entirely clear why Gonzales has been so much better through his last couple outings. According to the man himself, he feels that he was only 60-70% last year. Now he feels like he’s 90-95%. Turns out, it helps to be healthy.
In the aforementioned article, Gonzales talks about how his curveball was his most affected pitch due to complications from his injury.
The numbers are in agreement with Marco’s reasoning. In 2017, hitters slugged .588 off of his curve. This year, they’re slugging just .364 off of it. FanGraphs concur with this sentiment, as his wCU/C (the value of his curveball) has improved from -2.76 to -0.31. It remains to be a good pitch, but it’s a big deal that it is no longer bad.
Gonzales has completely changed the way he’s utilizing his pitches. While he leaned heavily on his four-seam fastball last year, his changeup is now (just barely) his most used pitch and he’s throwing them all at more similar rates than he had previously.
But! Looking at it from year-to-year oversimplifies things. Especially because there hasn’t been a clear pattern that Gonzales has used his pitches this year.
As you can see, 2018 has been incredibly messy. In terms of pitch mix, his first three games were somewhat similar, and those games ended with a total of 11 earned runs in just 12 innings. Against the Astros, Gonzales leaned much more heavily on his cutter and curveball, while ditching his changeup. In his last game against the White Sox, he almost completely abandoned his four-seam fastball and used the combination of his sinker and changeup almost exactly two-thirds of the time.
Gonzales is experimenting with what works for him, which makes sense, because his sinker and cutter are both new pitches. Technically, the sinker is something he has used sparsely before, but he only used it in one game in 2017. Through this experimentation, Gonzales will, theoretically, be able to decipher which pitches are his best and how he can properly sequence them.
Coming out of college, Gonzales’ changeup was arguably the best changeup in college ball, and became one of the best in the minor leagues. There’s no doubt that it will be heavily featured in his repertoire. His sinker and cutter have been his first and second best pitches in terms of slugging percentage (.278 and .294, respectively). This is notable given they’ve both been introduced this year.
In 2017, Gonzales threw his four-seamer 47.93% of the time, and that usage is down to 21.84% this year. Although it appears he is starting to go away from it, it’s peculiar that Gonzales continues to use his four-seam fastball at all. The interesting thing is that it is, without question, his worst pitch. Hitters have slugged .578 and .650 off of it in 2017 and 2018, respectively, and his wFA/C (the value of his fastball) is listed at -3.28. That’s incredibly bad, and to make matters worse, the average velocity on his four-seamer has dropped from 92.11 to 90.86. (Although to be fair, his velocity is down in general.)
But Gonzales hasn’t only changed his pitches. He’s also discussed moving to a more natural arm slot. This has worked in the past for many others, including Mariners ace James Paxton. Once Paxton lowered his arm slot, his fastball became faster, and he became better. Curiously, Marco has seen his all of his pitches get slightly slower.
Below you can see that, on most of his pitches, the horizontal release point has moved by almost exactly half a foot across the board.
As for his vertical release point, it seems to have dropped slightly for his pitches. The error bars are still pretty wide at this point in the season, so it isn’t apparent exactly how much he’s adjusted his release point vertically.
Given all of these changes, there’s nothing to suggest Gonzales should be nearly as bad as his 4.37 ERA. The difference between his xwOBA (expected weight on-base overage; .335) and wOBA (.334) is nearly non-existent. His BABIP (batting average on balls in play; .406) and LOB% (left on base percentage; 62.9%) are also inflated. His FIP (2.60) and xFIP (2.41) suggest that he’s pitched a lot better than his ugly ERA shows. More precisely, his FIP and xFIP convey Gonzales (so far) as a ~2.50 ERA pitcher, not a 4.37 ERA pitcher.
Marco Gonzales has, in the matter of two starts, catapulted himself into relevancy and given Mariners fans some badly needed hope in terms of starting pitching. He also, for the time being, has made himself interesting. Whether his success is due to an arm slot change, new pitches, or injury recovery isn’t entirely clear. But just as with everything else in life, it’s likely a mixture of factors coming together to cause substantive changes in his performance.
Gonzales could come out and be miserable in his next start and we could go back to writing him off. This article would be all for naught! Boo. Surely, many pitchers have had elite two-game stretches before. Most pitchers, however, have not endured the amount of changes as Marco Gonzales has. For now, Gonzales is showing why he was once drafted 19th overall. It’s far too early to tell if Marco Gonzales is for real, but it seems reasonable to think that he’ll be serviceable. For the Mariners, that just might be enough.