The Change: Kevin Gausman or Nate Eovaldi?

Going into the season, we had two young fireballers with straight fastballs and meh results in their rear view mirror. Kevin Gausman and Nate Eovaldi both have good walk rate totals but bouts with homeritis and bad balls in play results that hint at bad command, or perhaps hanging secondary pitches. They’ve had incomplete arsenals, but they’ve recently added a pitch that threatens to make them whole. They’re in the same division, in ballparks that are better for hitters! They even had good starts last night! So… which one you got?

Eovaldi’s start last night was better. He no-hit the Rangers for six-plus and ended up with six strikeouts against two hits and two walks in seven innings. Even if the Rangers offense is struggling, that beats seven strikeouts against five hits and walks and a run in five innings in Tampa for Gausman.

But Gausman wasn’t ever going to go much more than five. He went five and two thirds in his last rehab start in Triple-A, and that team is probably going to take it easy with their young… ace? This wasn’t his first tango with shoulder tendonitis. There are at least two other reports of him dealing with the issue, and there’s a feeling in Baltimore that some of his up-and-down-again past with the Orioles has been due to their nervousness about that shoulder. Projections are right to give Eovaldi at least ten more innings going forward, and that number might be light.

Don’t give Eovaldi a pass, though. He had elbow issues late last year, and shoulder tendonitis of his own in 2013. He also recently started throwing a pitch that some have linked with injury. You’ll have to read my 2014 Hardball Times Annual piece to get the full story, but the fact that the marketplace of pitches hasn’t added more splitters despite the fact that the pitch has the best swinging strike rate of any pitch is probably meaningful.

It’s both good and bad that Eovaldi is throwing the splitter nearly a third of the time, then. Continuing the trend that he started in July last year, he’s really upped the usage of the splitfinger to the point that he’s actually throwing more splitters and sliders combined than four-seamers. In a way, he’s hiding his straight 98 mph fastball.

The fastball is where Gausman separates himself. Both have straight fastballs when judged horizontally, but Gausman’s has an inch-plus of ride over the average fastball. That should lead to pop-ups, and did last year, finally. It also leads to more whiffs than Eovaldi gets, even if they have both hit triple digits on the gun in games in the last calendar year. So Gausman is superior in one very important way: his fastball is better.

The secondary pitch that he added? That’s not as nice as Eovaldi’s splitter. Gausman added a curveball, and it gets below-average whiffs for its type. Eo’s splitter gets average whiffs, and since it’s a splitter, that means twice as many whiffs as Gausman’s curve. But! Gausman has had homer issues and the curve is good for this. His slider used to get spanked, but the curve has only allowed one fly ball in 207 chances — and not a single homer.

Since Gausman started with a splitter, this new breaking ball gives him a more complete arsenal. Eo started with a slider. Let’s look at what they’ve done since they made the big change to their arsenals!

Gausman vs Eovaldi Since Arsenal Changes

Pitcher	Start Date	Fastball%	Splitter%	Breaking%	swSTR	K/9	BB/9	ERA	FIP
Nate Eovaldi	7/1/15	44%	30%	27%	9.7%	8.3	3.0	3.72	3.11
Kevin Gausman	7/1/15	69%	19%	12%	11.2%	8.6	2.2	4.13	3.97

So this says Eovaldi is ahead on results, but there are two asterisks. Gausman actually threw more curveballs in his first start (26) than he had ever thrown in a start before (20 was his previous peak). He even got five whiffs, and that whiff rate is ahead of Eovaldi’s to begin with. So maybe he’s still figuring out his arsenal. And two, he’s ahead by strikeouts minus walks, which is a better measure than ERA.

These two guys are very similar. Maybe you give the park to Eovaldi, but you give the fastball to Gausman, the splitter to Gausman, the whiffs to Gausman. If you want to give results since arsenal change to Eovaldi, you have to admit that Gausman has had better underlying results. Right before you click on Gausman, you hesitate because of the shoulder thing… but Eovaldi has his own health issues. As hard as it is to say this after such a gem of a start from Eovaldi, I’m taking Gausman here.

The good news is that both are mixed-league relevant. Both are worth owning full stop. Both are probably worth starting all the time in the mean time, too. So the real answer to the titular question is: both.