Introduction
I had high expectations for Zac Gallen this season and for good reason. He was entering his walk year with one of the more talented rotations the team has fielded around him. It certainly seemed like the kind of ideal environment that would allow him to flourish one last time in the desert before moving on to greener, more lavish pastures. Instead, it’s been a nightmarish season for Gallen as his chances of securing a Fried-like deal this offseason have dwindled to a distant dream. His stock had fallen
so much that none of the pitching-hungry contending teams were willing to match even the modest price of a qualifying offer equivalent at this year’s Trade Deadline – quite the fall from grace for a player who was the unquestioned team ace just a couple years ago
But just like the rest of the team, Gallen seems to have resurrected his season in the month of August. For the month, he pitched to a 2.57 ERA, a 1.09 WHIP, and limited batters to a .220 batting average against (BAA) in six starts. Even more encouragingly, he’s been slowly turning it around for much longer than that isolated month. If you go back to the beginning of July until now, he actually owns a 3.42 ERA/3.28 FIP and a 1.10 WHIP in his last 12 starts. Those kinds of numbers won’t be winning anyone a Cy Young award anytime soon (although it might get you Cy Young consideration) or even earning an ace-like description, but they’re a far cry better than the 5.75 ERA/5.23 FIP and WHIP he had been sporting up to that point in the season. And now that he’s extended that streak of improved performance after last night’s gem, I wanted to take a look and see if there was a durable change in Gallen’s approach or arsenal that might explain the change or if it was simply a product of either small sample size or a change in luck.
Pitching Arsenal
I’ll admit, it’s rare for a starting pitcher to dramatically alter their repertoire in the middle of a season when the stakes are significantly higher. Of course, it’s nearly a Spring Training trope to hear stories about a pitcher learning a new pitch or adjusting their grip on an existing one. But those stories come at a time when the pitchers can workshop those changes with the entire pitching staff and in the comfort of meaningless Spring Training games or on a random backfield in Arizona or Florida – not at the end of a long, grueling season. Given those facts, it shouldn’t be surprising to see that Gallen hasn’t made any significant changes to his pitch mix in a single month. He’s still mostly leading with his four-seamer and knuckle curve (a combined 64% yesterday) with a changeup and another offspeed offering or two to keep hitters guessing. There were a couple interesting outliers in this stretch like his outing against the Rockies when he threw four different pitches nearly equally, but otherwise his repertoire has mostly stayed consistent so I don’t think this is the reason for this streak of success.
However, I do want to note the fact that there has been a noticeable improvement in the results Gallen has been seeing with his fastball. Since the beginning of July, he’s had 122 plate appearances end with his four-seamer. He yielded eight walks to 24 strikeouts and only allowed a .225 BAA. Conversely, between the beginning of the season and the end of June, there were 206 plate appearances that ended with that same pitch, but all of the peripheral numbers were worse. The righty handed out 20 free passes to just 35 strikeouts and posted a .249 BAA in that period. It’s difficult to overstate how important it is to Gallen’s performance that he can establish his fastball. In his best years, his fastball was one of the most valuable pitches in the league. If he can return to even a shadow of that, he is a completely different pitcher.
Luck or Small Sample Size
This feels like a bit of a cop out answer since it seems to be the stock answer whenever someone points out a particularly surprising statistical factoid. There’s certainly some validity to the complaint in this case since 12 starts probably only represents around a third of a full season’s workload for a starting pitcher. It’s much easier to have an excellent stretch over the period of a month or a few weeks than it is to have that same kind of performance over the length of an entire season. Amazingly, there doesn’t seem to be much evidence of that in this case though – at least as far as I can see. If it were strictly luck, we would see a significant difference between some of his expected stats which take into account exit velocity, quality of contact, etc and the actual results. In his first 17 starts of the season, Gallen allowed an expected BAA of .261 against an actual BAA of .252 – a small enough difference that it could be chalked up to any number of external variables. Meanwhile, during this recent stretch of success, he’s posted an expected BAA of .254 while seeing an actual BAA of .232. That’s a big enough differential to suggest there might be some luck involved, but it could also be a change in how well batters are actually seeing the ball. If we look at his hard hit rate between the two periods (46% in the first compared to 38% in the second), it’s reasonable to hypothesize that the batters are getting poorer quality contact, which might help to explain the differential between the batting averages.
Conclusion
Overall, there’s probably some amount of luck involved in Gallen’s seemingly sudden resurgence to excellence. But there’s also an argument to be made that he was hitting into some bad luck earlier in the year and this is the baseball gods’ way to balance those scales. I think the more likely scenario though is some additional confidence boosting his mental and emotional state while experiencing an uptick in the quality of his fastball has allowed his other pitches to shine through more effectively. The upshot of this change in performance? I suddenly feel significantly more comfortable extending a qualifying offer to the New Jersey native. If he can convince teams that his track record is long enough to warrant the kind of commitment that would beat out that offer, the team could easily net itself a compensatory pick. But if he were to accept the offer as additional protection, the team could then reasonably expect at least a steadying performance from the erstwhile ace.
