Kevin Gausman spent more than twice as much time in the majors in 2014 than he did in 2013. This time was probably enough to remove his "prospect" status; when you throw 160 innings in the bigs, you can’t be considered the next big thing anymore. Service time aside, the hype around Goose is still strong. He’ll turn 24 in January, so he’s still young, and he's demonstrated he can hang in the big leagues. The same can’t be said of his prospect-mate Dylan Bundy, who's two years younger but, thanks to Tommy John surgery, has only 1.2 innings in the bigs.
Gausman still has faced only 704 batters in the major leagues. In nerd speak this is called "small sample size" as it’s not even a full season for many pitchers. This means while it’s easy to explain what Gausman’s done, we should be very careful about predicting what he will do. So I'll try to focus on the former except where it’s clear that something different will happen next year.
One thing we can say about Gausman’s 2014 is that, superficially at least, it was better than his 2013. His ERA dropped from 5.66 to 3.57 and his FIP also dropped from 3.99 to 3.41. Not to mention, Goose got his first taste of the playoffs and did extremely well, striking out seven of the 27 batters he faced while walking just two and getting a ton of ground balls. However the devil’s in the details, and these particular devils show that Goose was actually a tiny bit worse in the regular season than he was in 2013.
Why do I say that? His strikeout rate dropped from 24.4% to 18.6% while his walk rate rose from 6.5% to 8%. The culprit behind these changes is Gausman's splitter, or rather, how batters' reactions to his splitter changed. In 2013, righties swung at his splitter 72% of the time. That rate dropped to 48% this year. Not only that, but lefties made more contact when they swung. In 2013, lefties made contact 40% of the time they swung. This rate jumped to 58% in 2014. These changing rates are important because, like all splitters, Gausman's is thrown out of the zone most of the time. If hitters aren't swinging, they are taking balls.
It isn’t a lack of break: the pitch gained nearly three inches of vertical movement in between 2013 and 2014. The data supports a couple theories. First, Gausman seemed to bury the pitch more often than not. In 2013 his average splitter ended up nine inches below the center of the strike zone. In 2014 that dropped to 15 inches below center. That’s well below most hitters’ knees. Second, he became more predictable. In 2013, when Gausman was ahead in the count against lefties, he threw the splitter about one-fifth of the time. In 2014 that increased to one-third of the time. Hitters may have learned that it was coming and chose to take the pitch.
Don’t get me wrong: I’m not saying Goose’s splitter is a bad pitch or that Gausman is a bad pitcher. Far from it. According to FanGraphs, his split was worth 0.58 runs per 100 pitches this year, 8th-most among pitchers with at least 80 IP. It got ground balls nearly 50% of the time. Hitters slugged (slugged!) only .300 against it.
I’m just saying that he may need to mix up its usage a bit in order to get hitters to swing and miss. Whatever change he made this year didn’t help his strikeout and walk rates. Look no further than his O-Swing rate. In 2013 it was 34.3%, which is very good. This year it was just 27.2%, which is below average. Great pitchers get hitters to swing and miss out of the zone.
The other major factor working in Gausman’s favor in 2014 was the astronomic drop in home runs allowed. It's why his FIP was better this year despite worse K and BB rates. His HR/9 dropped from 1.51 to 0.56. Put another way: he gave up one fewer home run this year despite facing more than twice as many batters.
That doesn’t pass the sniff test and indeed his HR/FB rate this year was a crazy-low 5.8%. This is regression to the mean in action: his 2013 rate was a gargantuan 18.6%! Just as we didn’t expect that rate to continue in 2014, so should we not expect his low 2014 rate to carry over into 2015. A few more balls will leave the yard against him.
The key to Gausman’s success in 2015 will be using his fastball to set up his splitter more effectively. If he can return to fooling hitters with the latter, he could be ticketed for another sub-4 ERA despite giving up more dingers. If he can’t get hitters to chase, he could end up with an ERA in the low-to-mid 4’s. That isn't awful, but it would be a disappointment for fans and definitely for Gausman as well. Of course choosing between "good" and "disappointing" is better than the choice Orioles fans have had for years, which was between "mediocre" and "terrible".
But the bigger question is: will Gausman be in Baltimore or Norfolk next year? Fans and analysts hope the answer is "Baltimore", but the rotation stalwarts of Tillman, Chen, Gonzalez, Norris, and Jimenez will all be back next year. There have been no indications of a trade and the team will definitely give Jimenez another shot in the rotation. I'm not good at armchair GM'ing, so I won't speculate. All I know is that he deserves a spot in the rotation.