Carlos Martinez is More Than Just a Fastball

The first thing you might notice when you watch Carlos Martinez throw are the numbers on the radar gun: 96, 97, 98. The Cardinals’ young righty throws the fifth-fastest four-seam fastball among starters in the big leagues, after all.

For all that velocity, though, the four-seamer might be his worst pitch. Among his pitches, it’s the only one that is not above-average by whiff rates, and it’s also allowed the highest slugging percentage on balls in play this year. “All the hitters who face me are looking for the four-seamer,” Martinez laughed when I pointed out that the pitch has his worst homer rate.

The pitcher’s response? Tighten up the rest of his pitches, one by one. That’s how he’s become a top-20 starter this year by strikeout rate, ground-ball rate, and ERA.

The Changeup

Carlos Martinez met with Pedro Martinez for some counseling, which is appropriate given the fact that some feel the young Dominican has the chance to be as good as his senior countryman. “He suggested I change from a four-seam changeup to a two-seam changeup,” the Cardinal said, and that grip alteration has been huge for the pitcher.

Like Jake Peavy before him, Carlos Martinez has found that the new changeup grip has completely changed the movement on the pitch. The pitch now drops three inches more than it used to, and fades almost four inches more.

As a result, the whiff and ground-ball rates on the pitch have all increased. “It used to be a change of pace, but now it is more of a swing-and-miss pitch,” Martinez told me through an interpreter. Research on effective changeups has suggested that movement is the most important aspect of a changeup. So the fact that his velocity gap has gone down a bit as the changeup has firmed up is not so important.

More important is that the pitch looks like this now. It’s gone from being below-average to having the fourth-best whiff rate among starters. And it’s probably not his best pitch.

The Sinker

The sinker has always been great. For his career, it averages 60% more whiffs than your average sinker, and 30% more ground balls, mostly by being the fifth-hardest sinker in the game while also featuring two and a half inches more drop than your average sinker.

It’s a nice pitch, but Martinez has added another half-inch of fade to the pitch this year by fooling around with his release point on the pitch a little bit. “I get more movement on the two-seam by being on the side of the ball a little more,” Martinez admitted.

You can see in the data that all of his release points have changed a bit this year, but that his release point on the slider has traveled further than it has for the rest of his pitches.


By getting around the side of it a bit more, he’s getting more movement on the pitch. By listening to Pedro Martinez about his mechanics, he’s improved his command of the pitch.

The Hall of Famer told the young Cardinal that he was flying open too often with his front shoulder. “I understand what he means,” Carlos said, “and I do it better now by using the moment when I separate my glove from my throwing hand to get better balance.” The sinker is a ball 15% less often this year.

The Breaking Balls

If you look at the different pitch classification systems out there, Martinez throws either a slider or a curve, but only throws one breaking ball. That’s not really the case — he has a slider and a curve — but Martinez agrees “they’re not that different.”

That doesn’t mean he’s satisfied with them as they are. “I’m working to improve the slider,” Martinez said. It’s hard to tell what this means from a movement perspective, but let’s look at the movement and velocities of his breaking balls by season. Toggle the filter to get different seasons and watch the red blob at the top closely.

It looks like the red blob has moved right and the green has moved down and to the left.

You can tell the harder breaking ball is not his favorite pitch — the number of breaking balls he’s thrown harder than 85 this year has gone down from 59% going into this season to 36% this season.

In the meantime, the curve has added sideways movement. There’s an extra half inch of horizontal movement on his breaking balls thrown slower than 84 this year. “The curve is a little loopier now,” Martinez admitted. And that’s good — big, loopy curves have more of a reverse platoon split than harder curves, so the curve has become more of a weapon against lefties.

So it makes sense when Martinez says he uses the bendier curve more against lefties. Southpaw batters hit .407 off of Martinez’s breaking balls last year, and this year, that number is down to .226.

And that harder breaking ball with less drop that he uses against righties? Even if he’s throwing it less, it’s still working. It’s getting 16% whiffs against righties this year, decidedly above average even if you call the pitch a slider. Sliders get 13% whiffs on average.

When you watch Carlos Martinez pitch tonight, you may be wowed by the high-nineties velocity on his four-seam fastball, and that’s fair. It’s part of what makes him special. But if you want to know why he’s been so much better this year, it was his work on the sinker, the change, the slider, and the curve that should catch your eye most.

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.

One Response to “Carlos Martinez is More Than Just a Fastball”

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  1. croggs says:

    Maybe I’m a Cardinals homer, but this was a good read. It’s hard to tell if the results are just randomness or something more sustainable a lot of times, this gives me a little more hope that it’s the latter. Great stuff as always, Eno.