Maximizing MacKenzie Gore's 4-seam fastball

MacKenzie Gore lives behind in the count. Last season, only five pitchers threw more pitches behind in the count than Washington’s 25-year-old southpaw. It’s not a new problem for Gore, who has always struggled with command: FanGraphs gives him a career Location+ of 98. But while some pitchers on the list manage in these situations (see: Dylan Cease), Gore is not one of them. 

Gore, Behind in the Count: .446 wOBA

League, Behind in the Count: .416 wOBA

Falling behind in the count is especially detrimental for Gore because his best pitch — a four-seam fastball — loses its value. Gore’s four-seamer has proven pedestrian (.346 wOBA, -2 RV, 38th percentile CSW) despite plus shape (league-best 124 Stuff+). The success rate for his FF varies drastically depending on the count. 

Gore’s FF, Behind in the Count: .465 wOBA // .436 xwOBA // 19.4% Whiff Rate

Gore’s FF, Ahead in the Count:  .231 wOBA // .250 xwOBA // 24.4% Whiff Rate

Why the discrepancy? A lot of it boils down to fastball location. When he’s behind in the count, Gore comes in the zone with his FF at a rate 10% higher than when he’s ahead in the count. That’s logical: He has to throw a strike. 

But Gore’s FF is significantly more effective when elevated, where he can take advantage of its shape. Last season, Gore modified his release point, throwing from a lower plane to create a flatter fastball. Coupled with the fact that his FF generates 2% more rise (IVB) than league average, the pitch is increasingly difficult to hit when located upstairs. The intersection of these attributes is quantified via Alex Chamberlain’s public VAA dashboard, which notes that the VAA of Gore’s FF is 0.25 degrees above average. 

Gore’s FF, In Zone:        .362 wOBA // .350 xwOBA // 18.7% Whiff Rate

Gore’s FF, Out of Zone: .308 wOBA // .339 xwOBA // 38.5% Whiff Rate 

And so Gore is stuck. His FF is significantly better up and out of the zone, a spot that he can’t exploit when he’s behind in the count. And since Gore is constantly falling behind in the count, he isn’t able to maximize his best pitch. Sure enough, no qualified pitcher threw more FFs behind in the count than Gore did last season. 

There’s also a predictability factor at play here. In September, FanGraphs’ Kiri Oler embarked on a fun quest to find baseball’s most predictable pitcher (IP > 100). Gore ranked 10th-highest in Oler’s initial ‘Predictability Score’ and fifth-highest in three-ball counts specifically, when pitchers are forced to rely on pitches that they can throw in the zone. 

Oler’s exploration certainly leaves room for nuance — factoring in pitch quality could be useful — but it nonetheless confirms our concerns with Gore. Only two full-time starters threw a higher percentage of FFs than Gore did last season. And while Gore has steadily reduced his FF usage in each of the last two years, his current arsenal limits any potential further reduction. Gore just doesn’t have enough options to attack hitters once he falls behind. And hitters know it. 

But here’s the thing: Gore knows it, to. In September, we saw the faint outlines of an adjustment. In 1-0 and 2-0 counts, Gore threw his FF marginally less often than he did the rest of the season. He relied more heavily on his curveball as a pitch that he could place in the zone. And while the sample size is aggressively small, both pitches reaped the benefit: .327 wOBA for his CU, .364 wOBA for his FF. 

I don’t want to read too much into these adjustments, but I do think it’s meaningful to recognize that Gore is aware of his problem. I wonder what sort of alterations he might make with an entire offseason to experiment. Perhaps he becomes the latest pitcher to carve a niche for a sinker. 

Starting pitchers embraced the quasi-sinker renaissance in 2024, just not in the ways you might think. In 1-0 and 2-0 counts, for instance, sinker usage among SPs actually reached a new nadir in the StatCast Era. And yet, in these specific counts, SPs found more success with their sinkers in any single-season in the past decade. There’s a path here for Gore to pursue and, by some, it’s already being exploited. 

Like Gore, Bryce Miller (124 Stuff+) and Luis Castillo (120 Stuff+) tout some of the best FF shapes in MLB. But Miller and Castillo are far more successful with their FFs than Gore is: 

Miller: 14 RV // .261 wOBA // 42.3% Usage Rate

Castillo: 18 RV // .278 wOBA // 45.3% Usage Rate

Gore: -2 RV // .346 wOBA // 55.3% Usage Rate

What can Gore learn from Miller and Castillo to best weaponize his four-seam fastball? 

Part of the answer, I think, comes down to a sinker. Sinker-ballers may no longer be common, but throwing a sinker is en vogue again. As Justin Choi wrote in his piece, “One Fastball Isn’t Enough,” sinkers with mediocre shapes are actually playing up due to their fit within a pitcher’s arsenal. Plus, pitchers have embraced the idea of working multiple fastballs in conjunction with one another. 

But why a sinker? Well, sinkers fit a dual-purpose model. Yes, they can fill up the zone. However, it’s not enough for a pitch to simply land in the strike zone. Sinkers, though, are uniquely capable of suppressing damage due to their ability to keep the ball on the ground. In that sense, it would be logical to throw a sinker in situations where damage is often done — for instance, when a pitcher is behind in the count. 

Sure enough, Miller and Castillo follow this blueprint. 

SINKERS	Overall	Behind in the Count
Miller	17.1% .301 wOBA .350 xwOBA	24.4% .381 wOBA .350 wOBA
Castillo	18% .353 wOBA .357 xwOBA	22.3% .326 wOBA .367 xwOBA

Both pitchers rely more heavily on their sinkers after falling behind in the count. Castillo’s sinker becomes his weapon of choice in 2-0 counts, as he throws it 35.1% of the time. Not far behind, Miller deploys his sinker as his No. 2 pitch in 1-0 and 2-0 counts. 

The two pitchers turn to their sinker because their best pitches — Miller’s dastardly split-finger and Castillo’s wipeout slider — are neutralized when the hitter gains a count advantage. In these spots, Miller and Castillo have the luxury of choice; they don’t automatically defer to their FFs. A sinker guards against predictability and barrels, making it a better option than a FF. 

League Averages, 2024

Behind in the Count	Ahead in the Count
FF = .439 wOBA	FF = .229 wOBA
Sinker = .416 wOBA	Sinker = .257 wOBA
Cutter = .409 wOBA	Cutter = .250 wOBA

Last offseason, Justin Chen explored the purported benefits of throwing a second fastball. Chen concluded that pitchers experience diminishing returns when pairing a plus-fastball with a second fastball offering. Pitchers who complimented one subpar fastball with another tended to have more success. 

So how do we properly assess Gore’s FF, which has a strong shape but poor results? Maybe we can draw from Yusei Kikuchi, whose plus-shape FF (114 Stuff+) belied its productivity (.348 wOBA, .505 SLG). The Blue Jays maintained Kikuchi’s high usage rate — evidently a shape-based decision. But the Astros revitalized Kikuchi’s season by instructing him to throw his FF less, shelving the pitch in favor of his slider, and leading us to an existential question: When following the new-age premise of throwing your best page more often, should you lean on stuff or results? 

Perhaps Kikuchi’s tale is more about optimizing pitches than simply emphasizing your best pitch. Kikuchi didn’t simply rediscover his FF’s value by throwing it less often. Rather, he changed its role within his arsenal, instead using his slider as his weapon of choice when behind in the count. As such, he put his FF in a better position to succeed, using it in non-limiting counts. This is the roadmap that Gore should follow. 

It looks as if this could be an organization-wide flashpoint, too. From June 1 through the end of the season, three Washington left-handers — Gore, Mitchell Parker, and DJ Herz — ranked in the top-20 for FFs thrown behind in the count. Like Gore, Parker and Herz could certainly benefit from a repertoire that primes their FF for success, with a supplementary pitch that relieves some of the FF’s behind-the-count burden. 

FFs	Overall	Behind in the Count
Herz	52.2% Usage .288 wOBA 30.5% Whiff Rate	61.1% Usage .375 wOBA 27% Whiff Rate
Parker	48.6% Usage .329 wOBA 12% Whiff Rate	60.5% Usage .376 wOBA 11.7% Whiff Rate

Despite high-grade four-seam shape, Gore is yet to maximize the value of a potentially elite pitch. Refining his arsenal with a sinker — which can complement the four-seamer and suppress damage in poor counts — would better prime his fastball for success and allow him to succeed behind in the count. If Gore completes these changes, I’d expect him to tap into more of his potential as a fourth-year pro in 2025.