Learning From the Two-Pitch Pitchers

The conventional wisdom says that your starting pitcher needs three pitches. Fastball, breaking ball, change-up is best, but three pitches by hook or crook. If they don’t, they’ll have platoon splits and a tough time getting through the lineup. That’s largely true, of course, but there are always exceptions.

Let’s see what we can learn from the exceptions.

First, let’s list all the qualified starting pitchers that have two pitches that add up to more than 90% of their arsenal. We can learn from the best and the worst, after all.

Justin Masterson 77.9% 89.0 100.0% 4.51 3.01
Chris Archer 64.4% 94.5 97.2% 4.11 3.23
Wily Peralta 66.8% 95.3 96.2% 4.31 3.82
Tyson Ross 57.4% 92.3 94.9% 3.98 3.45
Chris Young 72.5% 85.3 94.6% 4.26 4.41
Juan Nicasio 69.8% 92.1 93.6% 4.97 3.50
Bartolo Colon 85.2% 88.9 92.7% 4.45 3.71
Garrett Richards 70.7% 95.8 92.6% 4.19 3.42
Matt Garza 65.8% 92.4 90.9% 4.00 3.95
Andrew Cashner 72.8% 94.0 90.8% 3.65 3.49
John Lackey 65.9% 91.8 90.6% 3.88 3.87
Jason Hammel 60.5% 92.2 90.4% 4.67 3.85
Wade Miley 64.9% 91.0 90.3% 4.00 3.26
Jarred Cosart 71.5% 94.0 98.4% 4.00 4.99
A.J. Burnett 61.5% 91.3 95.0% 3.77 3.80
Charlie Morton 68.4% 91.6 91.6% 4.78 3.76
Josh Collmenter 74.9% 86.3 94.2% 4.00 3.72

Justin Masterson is, of course, the poster child for this analysis. He’s had some great seasons for a man that was supposed to end up in the bullpen because he couldn’t find a change-up. And he has had some iffy platoon splits because of it.

Let’s look at those platoon splits. The average opposite-sided career FIP for the fastball+slider pitches is 4.23 (below league average) compared to 3.61 against same-handed players. So the conventional wisdom scores one here.

Chris Young is the only one with a reverse platoon split. We already spent some time talking about how Young is unique, but it’s worth showing something else here. He throws fastballs up in the zone, and it looks like lefties like the ball up less than righties. Check out the league average run value maps below. On the left is righties against righties, on the right is lefties against righties. See the top?


Perhaps, if you’re looking at a fastball/slider guy you might think is undervalued by his arsenal, perhaps you’re looking for a guy with a decent fastball that can pitch up in the zone. Matt Garza and John Lackey have the closest platoon splits other than Young, and Garza has high-in-zone tendencies against lefties, while Lackey actually lives high and tight against lefties.

Using this analysis to evaluate the younger names on this list is iffy — there’s no rock solid correlation here — but it’s at least interesting to compare them to the veterans with smaller platoon splits than their arsenals might predict. Tyson Ross lives down in the zone in general, but it is nice to see the high-and-tight Lackey-style tendencies in his heat map. Ditto for Chris Archer. Unfortunately, you can see the same heat map for Juan Nicasio, and he has the worst platoon split of the bunch (other than Justin Masterson). Masterson does *not* pitch up in the zone.

There’s also one way a pitcher can throw two pitches and avoid platoon splits — by throwing a few variations on their pitches. A.J. Burnett throws a knuckle slider and a knuckle curve, Luke Gregerson throws a few variations on his slider, and we know that Wily Peralta does the same thing. The same is true for Andrew Cashner. This is Garrett Richards‘ secret too, in a more conventional sense: he throws a curve ball fairly regularly.

The sample sizes on the curve and change guys are too small to say anything but: if your pitcher has a curve or a change as his second pitch, he may still be okay. We know that the platoon splits on those two pitches are more spread out than the platoon splits on breaking pitches. There are round-house curves and change-ups that have reverse platoon splits, even. That’s part of why it’s not *that* big a deal that Sonny Gray’s change-up is no good.

But when it comes to your young fastball/slider pitcher, it’s obvious that he’s not doomed from the beginning. If he can perhaps change sight lines with the high fastballs that lefties don’t prefer, and if he can develop a second type of breaker to change movements, he may have some hope. You’re still talking about a dicey plan, though — just look at the career of Justin Masterson.

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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I apologize if I missed this, but is there differentiation made here between different types of fastball (I see those between different types of curves, etc)? Are cut and 2-seam fastballs just lumped in with “fastballs” here, even though they may have significantly different movement and basically be different pitches than the straight 4-seamer?