Who Might Adam Warren Be?

It looks like Adam Warren has a spot in the Yankees rotation going into the season. And, according to our depth charts, he has a chance to hold that spot until at least Ivan Nova’s mid-season return. Given the health histories of some of the veterans ahead of him, that means he could start all year.

Could he start all year? What might we expect from him, given his arsenal and transition from the bullpen to the rotation?

Warren seems well suited for the transition. He regularly threw five pitches last year, as you might expect from a college starter coming out of a good program like University of North Carolina’s. It’s those five pitches, with examples all thrown in one five-out appearance last September 21st, that can give us a structure for this introduction.

Four-seam (-2.3 x-mov, 10.1 y-mov, 94.3 mph, left)
Two-seam (-6.4 x-mov, 7.6 y-mov, 94.0 mph, right)


That’s a straight four-seam fastball. It’s not so straight that it would end up on a leaderboard of the straightest four-seam fastballs, but it’s about two inches short of regular horizontal movement on the four-seam.

He makes up for that straightness in three ways. First, that vertical movement on the four-seam is about an inch more than average, making it a bit of a rising fastball. Rising fastballs are almost the most platoon-neutral pitch in baseball, so it’s a good weapon against both sides of the plate.

That vertical movement is almost on par with that of Chris Young’s fourseasmer (10.2), who talked openly of using that movement and the placement of his fastball to create pop-ups, and indeed vertical movement is related to pop-up rate. Warren’s pop-up rate is 3.7%, just a bit above league average (3.3%), but perhaps a bit of a change in where he places the pitch could make a difference. He’s mostly still down and away with the pitch to righties, and a few more up top might get him more pop-ups:


The second way he makes up for the straightness is with velocity. His 94 mph fastball velocity last year was two ticks above average for a righty. But that was in the pen. Early scouting reports had him more ‘low 90s,’ and we know that moving from the pen to the rotation can cost you about 0.7 mph on average. That means Warren should still have above-average velocity, unless he’s an outlier like Joba Chamberlain and Phil Hughes, who both lost about two mph in similar situations. Then he’d be average.

He’d still have the third thing that makes his fastball mix play up. His (newish) sinker. That sinker doesn’t have the drop of some of the premier sinkers in the game (about an inch less than average), but it does have good fade. That’s almost two inches of fade over average, and a full four inches more than his four-seam. Only 21 righty starters last year had a bigger gap in movement between their four-seam and two-seam, with Zack Greinke (-2.1 four-seam horizontal movement, -6.9 two-seam) being the most similar.

(-8.4 x-mov, 4.8 y-mov, 85.4 mph, 8.9 mph difference)


By almost every different way you can measure a changeup, Warren’s change is good. It’s got two inches more fade than your average righty change, and is a half tick slower than average relative to his fastball. For his career, it’s gotten more whiffs (16%) and grounders (53%) than average (13% and 50% respectively).

Like his sinker, it doesn’t sink as much as average (a half inch less), but it does sink almost three inches more than his sinker. And it has more fade than his sinker, and a good gap in velocities. These things matter, as they are correlated to whiff and grounder rates and back up his existing results despite the medium-sized sample.

The change has always been considered his best pitch, and even though it doesn’t hit the elite whiff rates of other change-first guys, it does do well. It compares favorably, for example, to the changes thrown by Michael Wacha in terms of results (16% whiffs, 58% grounders) and Tanner Roark by shape and velocity (-8.3 x-mov, 6.2 y-mov, 9 mph difference).

The only question in transition is if his change will maintain the same difference in velocity when the fastball falls off. Since it has been his best pitch, the bet here is that it will make the transition.

(4.9 x-mov, 1.0 y-mov, 86.1 mph)


In the scouting report linked above, Warren’s slider is called a cutter. But in the PITCHf/x database, the league’s righties as a whole threw a slider that moved 2.6 inches horizontally and 1.4 inches vertically while going 84 mph. Cutters had values of .7, 6.0, and 89 respectively, so this looks more like a slider than anything.

Thankfully, it has some depth. Since the change and fastballs don’t, it’s nice to see a slightly hard pitch that has some drop to it. Considering he got 14% whiffs on the pitch, and it’s basically an average slider, it’s not surprising to hear that it’s something that he’s currently working to improve.

He only threw 13 sliders in 2012, but how many do you need to throw to judge a shape generally? Since that year, he’s added depth and horizontal movement, so he’s made progress. Not every pitch needs to be a standout pitch.

(4.6 x-mov, -5.5 y-mov, 80.6 mph)


Also in Mike Axisa’s excellent scouting report linked above is an item that the team had Warren put away the slider in order to work on the curve. What the pitcher got for his work was an average curve. Like, almost literally.

The average righty curve in the PITCHf/x database moves 5.6 inches horizontally and drops 5.6 inches, while going 77 mph. Warren’s curve is pretty close to the textbook. He could be Shelby Miller (6.6 x-mov, -5.5 y-mov, 77 mph last year), I guess.

Results have Warren just about as close to average. Last year, it got 12.5% whiffs, but for his career, it’s 9.7%. The 40th percentile curve got 9.5% and the 50th percentile got 10.5%. So far so good for our ‘curveball is average’ narrative.

Except when you look at the ground-ball rate for his curveball. 83% of his 308 curveballs that have been put into play have been ground balls. Last year, his 74% ground-ball rate on the curve was only bested by Carlos Carrasco and Joe Kelly (minimum 150 thrown).

That’s… outstanding. What makes it even more remarkable is that curve drop is the best predictor of a curve’s ground-ball rate, and Warren’s drop is average. Joe Kelly’s curve, for example, dropped almost three inches further than Warren’s. Eh, the correlation is not strong, and by being a slightly hard curve, perhaps batters are fooled into thinking it’s the slider at first. And he gets grounders by throwing it down in the zone:


All together now. We’ve got a righty with above average fastball(s) velocity and at least average command. A good change, an average slider, and a curveball that might only be average if it didn’t entice worm-burners at an elite rate. Can we find another pitcher that compares?

If you go from a strict comparison based on what Warren throws, there are 20 pitchers that come close, but four pitchers that stand out. Unfortunately, those four are so far apart in quality that it doesn’t help our case.

Name IP FA% FT% FC% SL% CU% CH%
Adam Warren 78.2 29% 9% 3% 31% 11% 16%
Zack Greinke 202.1 34% 21% 2% 18% 10% 16%
Kevin Correia 154 15% 17% 6% 30% 17% 15%
Jhoulys Chacin 63.1 23% 28% 3% 19% 13% 15%

He could be Kevin Correia! Or he could be Zack Greinke!

Let’s return to that list of 20. Let’s take out the lefties (no more Mike Minor). Let’s remove the fastball velocities at the extreme — Felipe Paulino‘s 95.1 mph and Carlos Villanueva’s 88.7 mph career velocities don’t seem like possible outcomes for Warren. Let’s take out the guys that don’t have one above-average secondary pitch by whiff rates, so Ryan Vogelsong and Kevin Correia leave the list.

Now the list is shorter, and much more exciting. Here are the whiff rates for each pitch, for pitchers that had similar pitch mixes and velocities.

Name FA swSTR% FT swSTR% FC swSTR% SL swSTR% CU swSTR% CH swSTR% FBv BB%
Adam Warren 7% 6% 12% 14% 10% 16% ? 8.3%
Zack Greinke 7% 4% 14% 19% 10% 13% 92.9 6.0%
Erasmo Ramirez 7% 6%   11% 11% 21% 92.0 8.0%
Matt Cain 8% 5%   12% 8% 14% 91.8 8.2%
Homer Bailey 7% 6%   16% 10% 16% 93.2 7.6%

That’s a nice list. Only Erasmo Ramirez to tamper our expectations. Of course, listing walk rate as a proxy for command is flawed. Matt Cain is known for his ability to place the ball, or was. Homer Bailey’s change is a splitter, and it dips and dives much more than Warren’s — he might have more traditional ‘stuff.’

Also, Warren used his fastball much less often than anyone remaining on this list, and that was in relief. Correia was the only one that used his fastball less often, and on the short list above, Matt Cain’s 50% usage was the closest to Warren’s 39%. Unsure what to make of this, considering that the movement and velocity on the fastballs are decent.

But Zack Greinke? Could Adam Warren be anything like Zack Greinke? They’ve both got straight, rising fastballs complemented by good sinkers. Greinke’s slider is better than his change, and Warren’s change is better than his slider, but the ratio between the two pitches is similar. Neither curve is great, but Warren’s gets so many ground balls that it might shorten the distance between their respective abilities to command their arsenals.

Even if Adam Warren is Matt Cain or Homer Bailey in Yankee Stadium — which would mean a few more homers than those comps allowed — you’d have to be excited by this list of comps. Warren’s only thrown 158 innings so far in his career, and he never had the pedigree associated with the better names on this list, but as long as he can keep more velocity and command than Erasmo Ramirez, we may see a very nice season out of the Yankee’s fifth starter this year.

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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7 years ago

Interesting. His insistence on keeping the five pitch mix in relief is pretty big now.

I watch Warren and see a guy whose original pedigree was held down by a fastball that was slightly below average in velocity. The original projection had him as a sitting 89-91 maxing out at 93 guy. Bumping that to sitting 91-93 maxing out at 95 changes things.

Looks like the very definition of a solid mid rotation type to me.