Kevin Gausman’s first two months in an Atlanta uniform were definitely a mixed bag. Results-wise, there was little to complain about: a 70 ERA- and 94 FIP- were well below and marginally below his career rates, respectively. However, it wasn’t always clear how much of this success was actually Gausman, rather than just a change in circumstance. The right-hander’s strikeout and walk rates both went in the wrong direction, and his FIP improved as a result of a whiplash-inducing drop in his homer allowance. The result of these was that his xFIP during August and September 2018 was actually 110 (higher than any full-season mark he had posted previously), and there was potential cause for concern for his future if he didn’t right the U.S.S. Strikeout-and-Walk Rates.
But, despite a late start to 2019 owing to some usual pitcher bugbears (arm troubles), Gausman has actually more or less invalidated any concerns about the above, at least so far. Instead, he’s gone in a completely different (and awesome) direction. While his walk rate has continued to climb, his strikeout rate has skyrocketed, all the way up to 31 percent (15th in MLB among starters with ten or more innings pitched this year). As a result, he currently holds a 72 FIP- and 79 xFIP-, something only 25 pitchers with as many or more frames as him so far have managed to meet or beat so far this season.
Now, when thinking about Kevin Gausman, the narrative always focuses on a few key things: he has a hard fastball that doesn’t get great results, and a devastating split-change that he should perhaps throw more often. Indeed, “too many fastballs” and “throw the split-change, Kevin!” are probably common refrains from Braves fans that watched him pitch. Through his four starts in 2019, though, Gausman has flipped the script on that narrative.
It’s not that Gausman isn’t throwing the split-change more: he is, but it’s largely coming at the expense of his third pitch, a slider, which was never really any good and had little horizontal motion or ability to miss bats. But, the split-change, as good it is, hasn’t really gained or lost anything this year. You can see from the Baseball Savant snip below that it isn’t a huge difference-maker so far. Yes, the xwOBA allowed on it has dropped, but as a pitch whose goal is to get whiffs, it isn’t really leading to more of those or more punchouts.
The difference, as you’ve probably noticed in the above, has actually been Gausman’s fastball. Gausman isn’t throwing it any harder (though he has added some spin), but the results are striking in their difference from 2018. The whiff rate on it has increased by 60 percent, and it’s become as much of a strikeout pitch as the split-change.
Getting pitch results is the complex result of a repeated cat-and-mouse game. It’s hard to tell simple stories about why one pitch suddenly is or isn’t getting better results because there are so many interrelated factors. Could it be that throwing fewer sliders and more split-changes sets up the split-change better? Does adding 80 rpm of spin make a huge difference? Is greater avoidance of putting the fastball in the strike zone exploiting overanxious hitters? All of these and more? It’s hard to say with certainty.
But, there’s one thing that stands out to me about Kevin Gausman’s fastball, 2019 edition, that wasn’t really true before. Think broadly about fastball usage. Fastballs are generally the most common pitch, and, on average, a fastball is more likely to be thrown down the pipe than somewhere further away from dead center. (You can see this very clearly here; if you go through various pitchers like Max Scherzer or Andrew Cashner, just to name a couple, you’ll see that yes, pitchers do tend to throw their fastballs more or less around the heart of the plate more often than in other places.) The 2018 version of Kevin Gausman was also one of these guys, where by “these guys” I mean “pitchers.” The below is a set of heatmaps for Gausman’s pitch locations last year (2018), by pitch type. The fastball looks pretty similar to a generic fastball usage heat map.
But now, let’s look at 2019.
The split-change location is pretty similar, just more jagged due to a smaller sample size. The slider and sinker (the latter is potentially just a classification error) are used so infrequently as to not really matter. But the fastball is no longer oriented around the middle of the zone. Instead, it’s up and in to right-handers, and up and away to lefties. It’s actually spotted outside the zone quite often, especially compared to how Gausman used it in 2018.
One interesting thing here is that this usage doesn’t change much in terms of whether a lefty or righty is at the plate. Gausman has no compunction about running the ball up-and-in to righties, while keeping it away from lefties in nearly the same place. In any case, the frequency of fastballs hitting that location is pretty stark:
- 2018: 1,753 fastballs, of which 373 (21.2 percent) were in the arm-side-and-up area; versus
- 2019: 157 fastballs so far, of which 68 (43.3 percent) were in that area.
Overall, Gausman’s results on the pitch haven’t actually been as good — he allowed a .244 xwOBA on fastballs in that location last year, and it’s up to .280 this year. But, for fastballs in other locations in the zone, he allowed a .409 xwOBA last year (ew), and a .341 this year. By shifting his fastball location to a place where hitters do comparatively less with it, he’s capturing a broader benefit, even if the additional frequency perhaps makes the pitch somewhat more predictable. On contact, the difference is actually fairly stark, as Gausman really mitigated damage with that high fastball in 2018 (.263 xwOBACON) and hasn’t really done so in 2019 (.392 xwOBACON). But, that sort of misses the point — he’s going up there for whiffs, and living with the contact. Only 28 percent of swings on those fastballs get put in play (this ratio is unchanged between 2018 and 2019 so far), meaning there are lots of whiffs and fouls to be had.
Perhaps one worrying component is that this strategy necessarily involves not throwing as many strikes, both because the strategy directly entails throwing out of the zone (Gausman’s current zone rate is just 31.8 percent, easily the lowest among any starter with 10+ IP so far this year), and because if there’s one type of strike umpires are less inclined to call by the rulebook, it’s the high strike. But, it’s worked so far, and is the reason why Gausman’s contact rate allowed is currently just 71 percent, a top 25 mark in baseball (just like his overall FIP-/xFIP- marks), only a bit above names like Jacob deGrom and James Paxton. So long as things keep going the way they have so far, you can expect to see a lot of this:
And this:
Just one word of caution, which is especially relevant for Gausman’s start later tonight at the launching pad in Cincinnati: this isn’t really a good idea if opposing batters have a sense that it’s coming. Watch out for this.
And, you know, when in doubt, maybe throw the split-change?