Surprise! Aroldis Chapman isn't as unhittable as you think

If you get ahead in the count against Aroldis Chapman, you just may have a chance to get the best of him. Jonathan Daniel/Getty Images

There are two things I suspect every pitcher who ever stepped on a major league mound have in common: They all said, at some point:

And they all failed to imagine Aroldis Chapman.

"I've thrown it up near 100 mph sometimes," Roger Clemens once boasted. "But, little man, if you throw it 97 down the middle it's going to go a long way."

This is absolutely true. Major league pitchers threw 1,206 pitches this year that were between 96.5 and 97.49 mph, that were in the middle third of the strike zone vertically, and that were in the middle third of the zone horizontally. Major-league batters hit .350 on those pitches. They slugged .613. They homered on 1 in 17 of those pitches. They hit, as a league, almost exactly as Miguel Cabrera did the year he won his second MVP award.

Almost every pitcher is bad when he throws the ball there, no matter how hard he throws it. Noah Syndergaard, when he throws it right down the middle, has allowed a .543 slugging percentage in his career. Dellin Betances has allowed a .556 slugging percentage. Andrew Miller, .484; Chris Sale, .515; Madison Bumgarner, .529; Max Scherzer, .562. Even Clayton Kershaw, who I've written is the king of down-the-middle excellence, has allowed a .399 slugging percentage on such pitches, 100 points higher than his opponents have slugged against him overall. Mariano Rivera was only nine points better than Kershaw, at least in the years after PITCHf/x was introduced in 2008.

Then there's Chapman (note -- all numbers are regular season only). In his career, batters have slugged .311 off his pitches down the middle. This year, it was .231, as he threw 106 pitches down the middle without allowing an extra-base hit. When it's a fastball down the middle, batters slug .317. When we talk about the best pitch in baseball -- Chris Archer's slider, or Kershaw's curveball or Felix Hernandez's changeup -- we might include Aroldis Chapman's pipe shot.

Consider: Chapman has thrown 554 pitches down the middle in his career, and batters have swung and missed at more than a third of them. It's not just the highest whiff rate in baseball, no other active pitcher is higher than 26.5 percent, and Chapman's whiff rate is more than five standard deviations from the mean. I mentioned this to Dan Brooks, of Brooks Baseball, and he responded: "‪Stephen Hawking has a 160 IQ‬, which means Chapman is better at getting whiffs in the middle of the zone than Stephen Hawking is smart.‬" (The IQ scale is based on standard deviations, where the population mean is set at -- actually, forget it. Just trust Dan.)‬‬

Consider, as well, that he's roughly as tough to hit when he throws it down the middle as when he throws it anywhere else in the strike zone:

Most baseball skills actually require a whole bunch of subskills working together. You can't just be fast to be a good outfielder. You must be fast and have a quality arm and know how to track a baseball and be able to hold on to it. You can't just be a big, strong guy to hit homers; you must be able to hit breaking balls, fastballs, inside and outside pitches, to identify pitches and adjust as you go. You can't just have a good curveball or a good slider to strike batters out; you must have multiple pitches to keep hitters from sitting on your primary pitch. If you're blessed enough to defy this last rule, like Mariano Rivera was and Zach Britton and R.A. Dickey are, you must still put the ball close to where you want it to go. (Down the middle when Britton throws it: .502 slugging percentage; R.A. Dickey: .541.) The inability of each player to master every facet of the game is what keeps balance in the game, what makes scouting reports useful.

Even pitchers who throw as hard (or nearly as hard) as Chapman have to do more than "right down the middle, just right there down the middle." The hardest-throwing pitcher of the PITCHf/x era is not Chapman, but a reliever on the Atlanta Braves named Mauricio Cabrera. A 22-year-old rookie this year, Cabrera has averaged 101.1 mph with his fastball in his short career, more than 1 mph faster than anybody else has averaged and nearly 7 mph faster than the median pitcher's heat in 2016. Cabrera is fine -- he had a 2.82 ERA in the majors this year -- but he hasn't been dominant. He struck out fewer batters per nine innings in 2016 than hundreds of other major league pitchers. He struck out exactly as many batters, in exactly as many innings, as Tim Lincecum did. And when he threw the ball right down the middle, batters hit it. Not hard, to be fair, but they whiffed about half as often as they have on Chapman's fattest strikes.

Same goes for two pitchers whose perceived velocities, based on how close to the plate they release the ball, are faster than Chapman's. Carter Capps has a 20 percent whiff/swing rate and a .589 slugging percentage allowed on pitches down the middle. Jordan Walden: 16 percent, .540.

So Chapman has a singular ability to make "mistakes" in the middle of the zone and not just live but thrive. This raises the question of why Chapman isn't even better than he is. That sounds absurd -- over the past three years he has the third-lowest ERA in the game, the eighth-lowest WHIP and the highest strikeouts-per-nine-innings rate -- but there is seemingly no defense against his pitches. He can throw fastballs down the middle and turn the entire league into Jeff Mathis. How have two pitchers been even better than him at preventing runs? How have Pat Neshek and Mark Melancon and six others been even better at preventing baserunners?

The key is that there is, in fact, one way to beat him: ball one. Chapman can throw a fastball right down the middle and get away with it as long as he's ahead in the count. Put him behind the count, however, and he's barely better than the league as a whole. Here's Chapman's OPS allowed in pitcher's, batter's and even counts in his career, and the league's overall numbers in the same time period:

When Chapman is ahead in a count and he throws a pitch down the middle, batters' isolated power -- slugging percentage minus batting average -- is .036; when batters are ahead, it's .300. When he's ahead and he throws a pitch down the middle, batters hit .270 on balls in play; when he's behind, it's .444. His home run rate goes up by a factor of four. He still gets plenty of swinging strikes, but he becomes nearly hittable.

The difference is that when he's behind in counts, he throws fastballs 93 percent of the time, which might as well be 100 percent of the time for a batter trying to guess what's coming. Batters can ignore his slider and sit on the heater, take a big swing and connect enough to do damage.

When Chapman is ahead in the count, he still throws more fastballs than most pitchers do, but he throws the slider often enough -- roughly one in four pitches, plus a few changeups -- that batters have to expect something other than a fastball. The difference between knowing the fastball is coming and suspecting the fastball is coming makes all the difference.

What makes Chapman so great is that his fastball is unhittable, no matter where he throws it. But what makes his fastball unhittable, no matter where he throws it, is that he has a slider that batters have to take seriously when they fall behind in the count. And what makes batters have to take that slider seriously is that he locates it well ...

... right off the corner, low and away to lefties and down and in to righties, where good sliders find their purpose.

Surprise! This was about his slider all along. And Pedro Martinez was right all along.