Nate Eovaldi: No Fastball Is Too Big to Hide

For his career, Nathan Eovaldi has a below-average strikeout rate. He’s been a little bit worse than league average by ERA, and a little bit better than league average by FIP, but even average is a strange outcome for a guy with a top-ten fastball by velocity.

Take a look at how much of an outlier Eovaldi is in graphical form. That’s him highlighted, against all starters that have thrown at least 1000 fastballs since 2007.

He should at least have an average strikeout rate, it looks like by this graph.

Two things first come to mind when you see a graph like this: straight fastball or terrible secondary stuff. Let’s take them in order.

Let’s re-do the graph from above but focus on the fastball. Here’s fastball velocity graphed against fastball swinging strike rate. Eovaldi is still an outlier, but when we graph the fastballs like this, we can use the color to highlight the straight fastballs. After flipping lefty fastballs so that all horizontal movement is on the same scale, we have to split all fastballs into three bins. The straightest fastball is, after all, very different from the average fastball and probably gets some benefit from that fact.

Eovaldi is once again highlighted, but remove the highlight and you’ll see a trend: the straight fastballs are mostly under the line, showing fewer swinging strikes than you’d expect given their velocity.

We know that horizontal movement is correlated to ground ball rates, so it’s not too surprising to see some red fastballs below the line — those are secret sinkers, or four-seamers with a lot of horizontal movement and good ground-ball rates. And the green fastballs above the line? Those are secret cut fastballs, or fastballs that look like four-seamers but have slightly cutter-like horizontal movement. Those get more whiffs.

So Eovaldi’s fastball is straight, and that robs some of his effectiveness. How about the second part? Are his secondary offerings no good? This time, let’s convert his swinging strike rate byt pitch type into indexed stats, where anything above 100 is better than league average.

Nate Eovaldi Pitch Types Versus League Average
Pitch Pitches SwStr% SwSTR+
Fastball 5537 6.1% 95
Slider 2190 13.4% 93
Curve 893 7.2% 69
Sinker 530 4.9% 94
Splitter 350 16.9% 104
Change 228 9.2% 67

Yes. Eovaldi’s secondary stuff is not really good. Until this season, every single one of his pitches was worse than league average by whiffs.

So why are we writing about a pitcher that is less than the sum of his parts? Because something has changed… again. Take a look at his splitter movement over the course of this season:

Brooksbaseball-Chart-25

His catcher confirms, Eovaldi changed something about the pitch. Below is the grip he used to have, which he showed me in Oakland, about five games before he changed the grip. “Right after the Miami game,” is when Eovaldi’s splitter took off, Brian McCann told George King of the Post. “Before that it was more like a forkball. Now there is amazing action on it.”

EovaldiSplitter2
The old grip on Eovaldi’s splitter.

Connecting the dots, it looks like Eovaldi is now holding the pitch more in his finger tips, and the velocity has gone up (it’s more 89 than 85 now), the horizontal movement has gone up, and he hasn’t lost any drop. It’s a great pitch now that he’s ‘tweaked’ it.

The whiff rate on the pitch is unchanged. That might seem strange, but this is how we circle back around. The whiff rate is unchanged, but Eovaldi is now throwing his splitter nearly a third of the time, and that’s the most he’s ever thrown a non-fastball. The whiff rate is unchanged but he trusts the pitch and it has remained good even as he’s gone to it more.

EovaldiSplitter
The new movement on the splitter Eovaldi now trusts.

Take a look at Eovaldi’s pitch usage over the last three years. He’s slowly thrown that straight, underperforming fastball less and less.

Brooksbaseball-Chart-26

Over the course of his career, Eovaldi has thrown the fastball two thirds of the time in zero-strike counts. Since he started throwing his splitter more, he’s thrown the fastball 43% of the time in those counts. In a way, he’s hiding his fastball. His 97+ mph fastball.

Since Eovaldi has changed his splitter movement and usage, he’s struck out 18% of the batters he’s faced, which is much closer to league average than usual for him, and about 12% better than his career average before this year. His ground ball rate has surged to 55%, or 25% better than his career average before this year. He’s a better pitcher now.

Sometimes people wonder why we write about pitchers like Nathan Eovaldi. It’s because velocity is a great place to start. In his last start, Eovaldi hit triple digits in the seventh inning. Sure, his fastball is straight, but even a straight fastball, at 102, in a spot where you might be expecting the 90 mph split-finger… that might look like this.

EovaldiFastball
This 102 mph fastball came in a 1-2 count.

No fastball is too big to hide. And now Eovaldi looks like he has the splitter to help hide it.





With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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DNA+
Guest
DNA+

As a Yankees fan I’ve gotten to see almost all of his starts. He looks better and better each time. I am getting rather excited by the potential. ….also, have to give the Yankee’s coaching staff a bit of credit for immediately teaching him a splitter to pair with the fastball.

Hugh
Guest
Hugh

Does he? His game log doesn’t scream improvement to me and I’m also watching every Yankee game (but haven’t felt what you’re articulating). FIP continues to think his BABIP is inflated, but given 4+ years of data now I’m beginning to think that his steady state BABIP level is in reality north of .300. I’m glad that he’s been inducing more ground balls, but until he either throws more strikes or gets more swings & misses he’s still going to get bogged down in high-pitch counts and require 110+ pitches to go 7 innings.

Would love to hear people’s thoughts (particularly Eno’s) about how does this change enable him to become a #2 starter instead of a #4. Fangraphs loves writing articles about Eovaldi but I don’t yet see how these changes/tweaks get him to be the pitcher they think he can be.

Hugh
Guest
Hugh

To be fair to Eno… I love this article and how it highlights existing and changing phenomena, but I feel it lacks the “and this is how he will become a better pitcher” part. To put it more bluntly, why should I care that these changes have occurred?

Hugh
Guest
Hugh

HA! Perfect. That’s what I was missing… Thanks man!

Frank
Guest
Frank

Is you look at his batting against, he’s gotten better in every category on a monthly basis. He is very much improved. His splitter has been so good that Keith Law recently dubbed it “best in the league.”

Rob
Guest
Rob

I see quite a bit of improvement, although I don’t see someone who will be a #2 starter. I’m sure the Yankees would be fine with a #3, and I suspect that’s where he’ll rank out, especially as he gains more command of the splitter. I believe David Cone said it took him a couple of years to master it, and Eovaldi is no Cone.

I know there is an infatuation with the artificial 100-pitch mark, but it shouldn’t be the same with all pitchers. Eovaldi clearly has a strong arm and doesn’t seem to get easily fatigued. As he masters the split, it would be to the Yankees advantage to bring Eovaldi up more regularly to the 110+ pitch count.

Satoshi
Guest
Satoshi

I don’t man, I’ve watched every start of his this year and it seems like he has the worst BIP luck of any pitcher I’ve seen. I’m sure it’s just selection bias, but he always seems to allow an extra run or two because of bad luck on balls in play. Take his last start. He was dominating through the first five innings, best I’ve ever seen him, and then in the 6th, he allowed an infield single, a weak tapper past short, another infield single a few batters later and all of a sudden, a brilliant performance turns into 3 ER. It really does seem like in Nate’s case, the performance really is better than the ERA, at least over the last few months.