Zac Gallen Makes His Cy Young Case

Zac Gallen couldn’t even wait until the sun went down to thumb his nose at my attempt to sort out the NL Cy Young race — or at least at the notion that he was out of it. While I mentioned Gallen in passing in a piece focused on Spencer Strider and a few other pitchers who appeared to have the best statistical cases for the award, I had little to say about Gallen, who spent much of this season as the league’s frontrunner but has faded in the second half, and was coming off back-to-back bad starts that had further puffed up his numbers. On Friday afternoon, the 28-year-old righty threw a three-hit complete-game shutout against the Cubs in a 1-0 win, prompting me to take a second look at situating him within the race as the candidates head into the home stretch.

Building off a 2022 campaign in which he posted a 2.54 ERA, 3.05 FIP, and 4.2 WAR en route to a fifth-place finish in the Cy Young voting, Gallen jumped out to the front of the race early this season. He ran off a streak of 28 consecutive scoreless innings from April 4–26, with an eye-opening 41-to-1 strikeout-to-walk ratio along the way. He finished June with a 2.72 ERA and 2.06 FIP, led the NL in FIP (2.85) and fWAR (3.8) at the All-Star break, and earned the starting nod for the All-Star Game opposite Gerrit Cole. He’s been the consensus pick for the Cy Young in four monthly polls of MLB.com voters.

That said, Gallen has had stretches where he’s been pretty ordinary. He allowed 10 runs (nine earned) in 10.2 innings in his first two starts of the season, against the Dodgers and Padres; putting up a zero in his final frame on April 4 began the aforementioned scoreless streak. He’s pitched to just a 3.76 ERA and 4.13 FIP since the All-Star break, even including Friday’s shutout, in large part because he entered that game having allowed 11 runs in 10.2 innings across his last two starts, against the Dodgers and Orioles. He’s allowed five runs or more in seven starts, two more than any of the other pitchers I mentioned in Friday’s roundup; Strider and Jesús Luzardo have five apiece, Justin Steele and Zack Wheeler four, Logan Webb three, and Blake Snell and Kodai Senga each just one. Here’s a look at his six-start rolling ERA and FIP for the season, showing a lot of time spent with both of those marks above 4.00:

Gallen hasn’t had a truly awful stretch, but he did post a 4.45 ERA in July, and had monthly FIPs above 4.00 in June, July, and August, driven largely by a flurry of home runs. After allowing two homers in his April 4 start, he went 10 starts and a total of 66 innings without giving one up, the second-longest streak this season (Sonny Gray went 11 starts and 66.2 innings). That took him through May; over his 16 starts from June through August, he served up 18 homers in 100.2 innings, capped by a four-homer game on August 28.

Those homers hint at why I swept Gallen aside in my previous analysis. He’s been hit unusually hard this season. Here’s a look at his rolling hard-hit rate, which has been quite out of character:

And here are his Statcast numbers for the past four seasons, starting with his abbreviated breakout 2020 campaign:

Even when he was scuffling in 2021 en route to a 4.30 ERA and 4.25 FIP, Gallen did a better job of limiting hard contact than he’s doing this year. His 3.7-mph increase in average exit velocity relative to last year is the largest in the game, atop a leaderboard where most of the other high-ranking pitchers have been injured, terrible, or both (Carlos Carrasco, Marco Gonzales, Dylan Cease, Germán Márquez, Eric Lauer, and Carlos Rodón are second through seventh, with Cease the only one above 0.6 WAR). That 91.5 mph average exit velo places Gallen in just the third percentile, and his hard-hit rate in the sixth, down from the 65th and 64th last year, respectively. Meanwhile, his barrel rate is in the 24th percentile, down from the 39th. In terms of his pitch selection, Gallen’s xSLG on three of his four most-used offerings has climbed substantially from 2022: his four-seam fastball from .356 to .444, his curve from .243 to .350, and his cutter from .350 to .551. He’s lost 0.5 mph of velocity and over 100 rpm of spin on his fastball (from 94.1 mph and 2,420 rpm last year to 93.6 and 2,302 rpm this year), with an even bigger dip in June that may have contributed to his struggles. On the other hand, he’s gained a bit of velocity on the curve, subtly altering its movement. The Stuff+ model considers all but his changeup (for which his xSLG has fallen from .399 to .356) to be above-average nonetheless, but the PitchingBot model (which uses a 20–80 scouting scale where 50 is average) views his cutter as having declined by a grade and a half:

Note also that the PitchingBot model views Gallen’s overall stuff as dropping from above-average to average, with his plus command mitigating the decline somewhat.

Gallen has acknowledged his increased propensity for hard contact, shrugging it off while occasionally conceding he’s lacked feel for one pitch or another. “You check the box score the next day,” he said after one August start, “they never say you gave up an out that was 900 mph [off the bat]. Sometimes, it’s better to be lucky than good really. My job is to get outs how ever they come. It’s fine by me.”

The good news is that the Diamondbacks have one of the game’s best defenses; their 40 DRS, 23 RAA, and 21.9 UZR all rank among the majors’ top five. What’s more, even if Gallen is giving up too much hard contact, he’s still plenty capable of missing bats. His 26% strikeout rate is eighth among qualified NL starters, and his 5.2% walk rate is the league’s sixth-lowest; combine those and his 20.8% K-BB% ranks fifth. Despite the gains in xSLG against some of his pitches, he’s raised his whiff rate on his curve (from 33.7% to 41.5%) and cutter (from 15.7% to 22.1%) as well as his changeup (from 25.3% to 29.4%).

And even with that hard contact, Gallen ranks fourth in FIP (3.26) and fifth in ERA (3.31). Spread that performance across 187.2 innings (second in the NL) and you have a pitcher whose 4.7 WAR is tied with Strider and Steele for second, behind only Wheeler’s 5.7. By Baseball Reference’s version of WAR, his 4.5 mark is tied for second with Webb, behind Snell (4.8). His 15-7 won-loss record doesn’t mean much to me, but it looks Cy-ish, in that the subset of voters who are still sensitive to this kind of stuff won’t give it a second thought as they might when looking at Webb’s 10-12 record, or Wheeler’s 11-6. Then again, I’m probably overstating the case given that Jacob deGrom won back-to-back Cy Youngs with records of 10-9 (2018) and 11-8 (2019).

In other words, particularly after Friday’s start — which, I should mention, enabled the Diamondbacks to maintain a half-game lead over the Marlins for the third NL Wild Card spot — Gallen belongs right there alongside the others in a race that has no clear-cut leader. Yet I left him out of my table aggregating a bunch of metrics when it came to my take-home analysis, dismissing him mainly on the basis of his 4.14 xERA (he’s now at 4.06). So here’s a second look, with updated numbers for Steele, Senga, Snell, and Webb as well after their starts this past weekend, plus a methodological adjustment:

To refresh your memory or rekindle your ire, recall that I tried averaging ERA, FIP and xERA into something I call jERA, sticking my initial in front so you can properly place the blame. I then used jERA to cobble together a back-of-the-envelope approximation of WAR (jWAR), but what I should have done was use xERA to approximate xWAR. This time I’ve done that, by using 5.49 runs per nine (25% higher than the NL average ERA of 4.39) as the replacement level, incorporating each pitcher’s innings to calculate how many runs above replacement level he is, and applying a rough conversion of 10 runs to one win. I then averaged fWAR, bWAR, and xWAR together into something I previously called aWAR, but by the logic used in creating jERA, that aggregate should be jWAR.

Because he still has the highest xERA of this bunch, Gallen ranks seventh out of eight in jERA, but his advantage in workload is such that he climbs to fifth in xWAR and jWAR. While I won’t make any grand claim about the utility of that last metric, it does represent an attempt to balance several different inputs and find a middle ground. You’re free to use it or lose it.

With three weeks to go in the regular season, I don’t see any way you can look at these numbers and conclude that they point to Gallen as the rightful Cy Young winner, but then I don’t think the numbers provide a conclusive case for any of these guys. For voters, the choice will come down to a preference for which of these numbers (and perhaps others) and which narrative they prefer. Even so, it’s clear that Gallen belongs in this company, and just as it’s true for Snell, Steele, Strider, and Wheeler, I think he’s capable of using his next couple of turns to make a closing argument that he should be the winner.