The Big Kevin Gausman Breakout Has Arrived

With a mid-to-high 90s fastball that has touched as high as 101 MPH and an elite splitter that has generated a SwStk% over 20% every season of his career, a lot has been expected of Kevin Gausman. You figured that with a two-pitch foundation like that, he would be racking up the strikeouts and rank as one of the better pitchers in baseball on an annual basis. And while he’s posted a couple of seasons of sub-4.00 ERAs, the underlying skills just haven’t been super impressive, and he sports a career ERA of 4.31. That’s perfectly serviceable, especially in a hitter friendly home park for most of his career in the American League. Sure enough, his career ERA- stands at an almost perfectly league average 101. So he’s been fine, but not what fantasy owners hoped for.

Now in his second full season in the National League, and in what used to be the most pitcher friendly venue in baseball (with the park changes, I’m not sure where it would currently rank, but I assume it’s still pitcher friendly), the massive breakout might finally be happening. The SwStk% spike he posted last year, while spending some time in relief, has carried over, even though only four of his 31 innings this season have come in relief. In fact, his 14.8% SwStk% ranks seventh among all qualified pitchers (59). This is a big jump for Gausman, who despite owning what should be two elite pitches, had been fairly mediocre at generating swinging strikes. Before last year, his marks narrowly ranged between 10.8% and 11.3% from 2015-2018. That’s perfectly decent, but again, fantasy owners wanted more than just decent.

That SwStk% has jolted his strikeout rate, which has surged above 30% for the first time. In fact, before last year’s mid-20% strikeout rate, he had only mustered a mark as high as 23%, which, again, was disappointing.

He hasn’t necessarily gotten to this new strikeout level the way you might think. Often times we find that a pitcher starts throwing his fastball less frequently and revs up his best whiff pitch to an even higher frequency, and voilà, strikeout rate bump. Gausman has thrown his four-seamer at the lowest rate of his career so far, a rate that has now declined for three straight seasons. However, his splitter is being thrown less often than last year when he first enjoyed that SwStk% surge, and its usage has come back down closer to his 2018 level. That said, he has clearly thrown the pitch far more often over these past three seasons than he had previously. So it explains some of the surge compared to pre-2018 levels, but not compared to the last two seasons.

One of the biggest changes in his mix is actually throwing his changeup more than just a token amount. He has actually now thrown his changeup the same number of times as he has over the previous three seasons combined! While the pitch’s SwStk% ain’t close to the splitter, it’s better than the fastball, so it’s a good swap strictly from a whiff perspective.

Getting back to his fastball, its average velocity sits at its highest mark since 2016, after a two season dip where it sat just above 94 MPH. Now it’s back above 95 MPH, representing a strong rebound. It’s no surprise then that the pitch sports its highest SwStk% in Gausman’s career at 10.8%.

The baseball card results haven’t been there yet and that 4.65 ERA looks just like what he has been doing in two of the last three seasons. So, it’s easy to gloss over his name without even realizing what he has been doing that’s actually in his control. Of course, he also plays for the last place Giants, which makes it even easier to completely ignore him.

On the other hand, his SIERA sits at a career low 3.08, which ranks fifth best among all qualified pitchers. Over a small 31 inning sample size, SIERA is a far better predictor of future ERA than ERA itself, even though SIERA is meant to look backwards, rather than forwards. If Gausman is still sitting in your free agent pool, even in your shallow mixed league, I would have to imagine you have several players projected for worse rest of season value than Gausman to persuade you to make the switch.