Relievers become relievers largely because they can handle two pitches, but can’t reliably deliver three. Every now and then, you get a reliever, like Mariano Rivera, who has one pitch, and everyone knows it’s coming, and it’s still an elite offering, but that’s far from the model.
Chad Green, one of the more reliable bullpen arms for the Yankees over the past six seasons, is a two-pitch pitcher, but that second pitch has been a journey. He throws a hard, rising, better-than-average fastball, but the tale of his second pitch and his struggles to command it largely dictate his overall performance game-in and game-out.
First, let’s start with the fastball. I think Green gets an unfair rep for having a mediocre fastball, but he really doesn’t. He doesn’t throw it quite as hard as Gerrit Cole, averaging about two miles per hour less than the Yankee ace, but both see about 2.5”. or 20 percent more “rise” than average. This means their fastballs are spinning so tightly they drop less on the way to the plate, ending higher than a hitter’s brain projects, giving the appearance the ball rose. This is, quite plainly, why fastballs are effective.
But Green has really had trouble finding another pitch:
Green’s slider was an extremely hit or miss pitch, being one of the more valuable breaking balls on the staff in 2016 and 2017, before completely cratering in 2018. Spin rate doesn’t work quite as neatly for sliders as other pitches, because sliders are nonsense pitches, but Green did add spin in 2018 and hitters were able to pick up on the pitch more effectively.
Over the past two seasons, Green’s ditched the slider for a curveball, and this season throws it about 35 percent of the time, a notable increase over 2020. Critically, he’s also gone to it more frequently to put away hitters, throwing it about 40 percent of the time in two-strike counts, about ten points more than last season.
Still, it’s not the most devastating curve in baseball, by any stretch. It’s a full standard deviation above the mean in spin rate, but almost exactly median in terms of active spin — only about 53 percent of the pitch’s spin contributes to movement, the rest is wasted energy. You can see that difference when you compare Green to someone with a real elite curve, like the Cardinals’ Alex Reyes:
This curve from Green is spinning at 2625 rpm, and breaks 38” down. MLB average is 40”, which is a real reflection on that ineffective spin I talked about above — less spin contributing to movement means the ball moves less, and also less sharply. A real hard hook is more deceptive, and Yuli Gurriel is able to identify the curve early in delivery, and lay off. Green gets the strike call, but that’s an example of poor umpiring, more than good pitching.
Contrast that with someone like Reyes:
This curve is spinning a little faster, but Reyes gets much more effective spin — about 99 percent of his spin contributes to movement. So what you have is a pitch breaking much farther, at 46”, and much sharper, so the pitch is more deceptive. This added deception not only will yield more swings and misses, but it also means that you can feel more confident delivering the ball in the strike zone, earlier in counts, which is something that Green doesn’t do that much of.
Chad Green is a very good pitcher and I broadly feel very confident when he gets the call while the Yankees have a lead. Still, he’s had a tumultuous relationship with secondary offerings — giving up on his slider entirely, and struggling to add a curveball that’s as deceptive as it should be when your only other pitch is a fastball. Fortunately, pitch design and modification is something that can be, and often is, worked on in-season, so maybe Matt Blake can unlock a little extra spin and a little more hook, and make Green that much better.