Kevin Gausman Is Giving Batters Splitting Headaches

There are myriad reasons why the San Francisco Giants have been causing trouble in the NL West this season, crashing what was expected to be an exclusive party for the Padres and Dodgers. One of them is the starting rotation, which generally ranks in the top five in baseball whether you go by simple stats like ERA (third) and ERA- (fourth) or peripheral ones like FIP (second). Of the starting pitchers, none stands taller than Kevin Gausman, once a highly a touted Orioles prospect who has spent most of the last decade as a breakout candidate but hadn’t had that one big season. Wel, it appears he’s having it now.

At the top of the major-league leaderboards, there’s a lot of Gausman. Only Jacob deGrom has a better ERA among qualifiers, and that pitcher is having what could be a year for the ages. Gausman’s sixth in WAR, fifth in FIP, seventh in swinging strikes, and 10th in contact rate. And while he’s not likely to finish the year with an ERA anywhere near his current microscopic 1.27, his 2.20 FIP is an easy career-best so far and not explained entirely by the drop in league-wide offense.

So, what has changed for Gausman? The most obvious difference in the stats is the drop in home run total, a particular bugaboo for him at various points in his career. Playing in San Francisco instead of Baltimore has undoubtedly helped alleviate that concern, as has the decline in home runs in 2021, but just as with his overall FIP, it’s not just the environment. ZiPS’ peripheral home run estimator, zHR, sees his “true” home run rate as 2.1% of plate appearances, compared to his actual 1.7%. There’s been an interesting shift here; prior to 2020, ZiPS saw Gausman as the sixth-largest underperformer in terms of home runs allowed, allowing 130 homers where zHR expected to see only 108. Since joining the Giants, they’ve been a perfect match (13 homers vs. 13 zHR).

Nothing has drastically changed about Gausman. His exit velocities haven’t plummeted, he didn’t suddenly add 3 or 4 mph to his fastball, nor is there a new pitch in his repertoire. He’s still a pitcher who relies primarily on a mid-90s fastball and his fosh-esque splitter , a slower variant of the pitch that moves the splitter firmly in the camp of an off-speed pitch. (Orioles fans should be familiar with this offering because it was the bread-and-butter of Mike Boddicker in the ’80s.) There’s the occasional slider, a pitch that never really came into its own for Gausman and has been deemphasized in recent years, but he basically relies on the one-two punch.

Gausman’s fastball has been more effective than usual, but it’s the splitter that’s become otherworldly. We have pitch data going back to 2002, and Gausman’s splitter is already cracking the top 30 seasons:

Most Valuable Splitters, 2002-21
Name Season wSF
Dan Haren 2006 22.5
Roger Clemens 2005 20.4
Tim Hudson 2003 19.9
Curt Schilling 2003 19.2
Koji Uehara 2013 18.8
Kelvim Escobar 2004 18.7
Masahiro Tanaka 2016 17.8
Roger Clemens 2003 16.1
Matt Shoemaker 2016 15.5
Cory Lidle 2006 14.3
Mark Mulder 2004 14.2
Kelvim Escobar 2003 14.2
Roger Clemens 2004 14.0
Hisashi Iwakuma 2013 13.6
Freddy Garcia 2006 13.3
Chuck Finley 2002 13.0
Jose Contreras 2005 12.9
Mark Mulder 2003 12.8
Hiroki Kuroda 2014 12.8
Hector Neris 2016 12.6
Curt Schilling 2002 12.5
Tim Hudson 2007 12.1
Masahiro Tanaka 2014 12.1
Kirby Yates 2019 12.0
Jeff Samardzija 2012 11.6
Miguel Batista 2003 11.3
Hector Neris 2019 11.2
Matt Shoemaker 2014 11.2
Kevin Gausman 2021 11.0
Roy Halladay 2011 10.8

Remember, this is isn’t a rate stat, but a counting one, so putting that together in just two months is mighty impressive. The pitch’s underlying characteristics haven’t really changed, but Gausman’s usage has, especially against right-handed batters. Without a truly effective breaking pitch but a fantastic splitter, Gausman’s had a reverse platoon split most of his career, with a .720 OPS against lefties and a .791 OPS against righties. Against righties, he didn’t have a true out pitch, with the splitter being the best with a .202 BA and a .369 SLG. For 2020-21, those figures stand at .071 and .118 respectively, with a swing-and-miss rate nearly 10 percentage points better than in the past (55% compared to 46%). Statcast sees a lot of that low BA being real; Gausman has an xBA of .104. And again, while the pitch itself hasn’t changed, the usage has. Before 2020, Gausman was throwing the splitter just over a fifth of the time when ahead against righties; since then, he’s doing so nearly half the time.

Also new? Where he’s throwing it. Not only is Gausman using the splitter in the counts that you’d expect to see a wicked breaking pitch — if he had one — he’s now also locating the splitter more like something with a sinister bend.

Gausman’s Splitter vs. Righties
Year BA OBP SLG RPM PX (ft) PZ (ft)
2021 .060 .120 .094 1614 0.05 1.36
2020 .097 .129 .097 1654 -0.05 1.30
2019 .286 .386 .316 1560 -0.20 1.51
2018 .127 .241 .242 1442 -0.29 1.45
2017 .164 .301 .218 1618 0.02 1.39
2016 .200 .440 .286 1554 -0.48 1.21
2015 .333 .810 .391 1538 -0.42 1.32
2014 .211 .421 .250 NA -0.44 1.31
2013 .167 .333 .167 NA -0.20 1.68

Gausman’s splitters have come lower and more towards the center of the plate against lefties as well, but it was always an amazing pitch against lefties. Now he has an out pitch against righties, one that allows him to have a pseudo-breaking ball that’s better than his actual one.

Naturally, this improvement by Gausman is also now reflected in the projections. ZiPS always had a soft spot for him, but the chances of him being a Cy Young contender had mostly faded.

ZiPS Projection – Kevin Gausman
Year W L S ERA G GS IP H ER HR BB SO ERA+ WAR
2022 10 6 0 3.39 28 27 162.0 141 61 18 40 174 124 3.7
2023 9 6 0 3.49 26 25 149.7 134 58 17 38 157 120 3.2
2024 8 6 0 3.63 25 24 141.3 130 57 17 36 144 116 2.8
2025 7 5 0 3.63 23 22 131.3 121 53 15 34 134 116 2.6
2026 7 5 0 3.70 21 21 121.7 113 50 15 32 124 114 2.3
2027 6 5 0 3.80 20 19 111.3 105 47 14 30 113 111 2.0
2028 5 4 0 3.93 18 17 100.7 96 44 13 28 101 107 1.6

Gausman’s improvement is enough to push up his projections by about a win a year since March, a notable shift for a veteran pitcher. It’s moved him from solidly above-average to a reasonable All-Star candidate in years he’s throwing 180 innings or so. I obviously don’t have full 2022 projections yet, but 3.7 WAR would have ranked Gausman 12th among pitchers in the preseason projections in 2021, up from his actual ranking of 41st. It also suggests a pitcher who should get a contract this offseason in the neighborhood of Zack Wheeler’s five-year, $118 million deal with the Phillies. He also will hit free agency unencumbered by a qualifying offer.

It’s probably too soon to start talking free agency; Gausman’s job right now is to help the Giants shock the NL West. And if he finishes with the 15-5, 2.80 ERA, 5.0 WAR season he’s currently projected to by our Depth Charts, the Giants may have some rare odd-year postseason magic in them.





Dan Szymborski is a senior writer for FanGraphs and the developer of the ZiPS projection system. He was a writer for ESPN.com from 2010-2018, a regular guest on a number of radio shows and podcasts, and a voting BBWAA member. He also maintains a terrible Twitter account at @DSzymborski.

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