Aroldis Chapman is the most coveted reliever in this free agent class, and it’s not particularly difficult to see why. Armed with the most explosive fastball in baseball, the four-time All Star has dominated hitters since arriving in the big leagues in 2010, striking out almost 15 batters per nine innings pitched. He stands 6-4, has very long limbs, and owns a sweeping delivery that makes most left-handed batters wish they had never stepped foot in the box. Put it all together, and Chapman is in line to become the highest paid reliever in baseball next season. Of course, this presupposes that a team will look past Chapman’s domestic violence history. The Yankees and Cubs were able to rationalize that away in 2015, and while his past may scare some off this winter, there is almost no doubt that a team will break the bank for Chapman’s age 29-34 seasons.
Yet the last time we saw him on a mound, Chapman was anything but dominant. Summoned by manager Joe Maddon to protect a 6-3 lead in the 8th inning of World Series Game 7, Chapman promptly surrendered a double to Brandon Guyer and a game-tying, two-strike home run to Rajai Davis. Chapman was noticeably fatigued, pitching on no rest because Maddon had used him with a five run lead in Game 6. Indeed, TV commentators Joe Buck and John Smoltz commented in real time that Chapman’s fastball looked different than usual.
But just how different was “Game 7” Chapman versus “Normal” Chapman? To more rigorously answer this question, we turn to MLB’s glorious PITCHf/x data.
Even the most casual baseball fan can pick up on what makes Chapman a nightmare for hitters: he throws hard. Incredibly hard. To put his fastball in context, I thought it would be useful to compare the velocity and spin rate of every Chapman fastball thrown in 2016 to the league-wide average fastball. Spin rate is measured in revolutions per minute, and it’s an important metric because all else equal, the faster a ball spins, the harder it is to hit.
The league-wide average lines are calculated using data from both starters and relievers, so the picture would look slightly different if we subset the data to include only relievers (since relievers throw harder on average than starters). But further subsetting the data wouldn’t change the primary takeaway: the vast majority of Chapman’s 2016 fastballs were thrown harder and with more spin — often considerably so — than the league average fastball.
PITCHf/x tracked nearly 1,000 fastballs thrown by Chapman in the 2016 regular season and postseason. Below are the probability distributions of velocity and spin rate, along with the mean and standard deviation of each, for the portfolio of Chapman fastballs in 2016.
The left picture shows an incredible result: Chapman’s fastball velocity averaged over 100 mph this season. Averaged! Remember, the league average velocity on fastballs this season was roughly 93 mph, and the league average spin rate on fastballs was roughly 2,100 rpm. Using the above probability distributions, there is virtually a 100% probability that a given Chapman fastball will be thrown harder than the league average, and a 95% probability that a given Chapman fastball will spin faster than the league average.
The data confirm what we already intuited was the case. Chapman throws an absolutely monster heater.
“Game 7” Chapman
So what happened in Game 7, then? How was the baseball equivalent of a fire breathing dragon reduced to tears after giving up the tying runs in the biggest game of his life? Well, because baseball, for one. But also because “Game 7” Chapman might not have been the same as “Normal” Chapman.
Chapman threw 21 pitches in that painful eighth inning, 19 of which were fastballs. Those 19 pitches are isolated below, along with Chapman’s 2016 average fastball velocity and spin rate.
You’ll notice immediately that every eighth inning fastball was either average or below average in terms of velocity, and most were below average in terms spin rate. Granted, a slightly slower Chapman fastball is still harder than the vast majority of pitches thrown in the Major Leagues, and thus incredibly hard to hit. But the point is that they were not Chapman-esque fastballs.
Let’s highlight the Rajai Davis at-bat, in which Davis sent a 2-2 fastball to the concourse to tie the game at six apiece and send Cleveland into a (temporary) frenzy.
The black dots are the fastballs that Chapman threw to Davis, and the purple dot is the fastball that Davis rocketed down the left field line for the home run. The blue and red shaded regions represent one standard deviation from Chapman’s mean velocity and spin rate, respectively, and the gray region represents two standard deviations from Chapman’s mean velocity.
This graph proves what we suspected. The gopher ball Chapman threw to Davis was highly abnormal; it spun more than one standard deviation slower than average, and it was thrown with two standard deviations less velocity. How odd statistically is the pitch Davis hit into the seats? Based on the rest of Chapman’s 2016 fastballs, there was only a 14% chance he would throw a fastball that spun that slowly, and a 3% chance he would throw a ball with that velocity. 3%! Clearly, Chapman wasn’t Chapman.
Of course, Davis still had to make it happen. He still had to get the barrel to a middle-in fastball thrown over 97 mph in Game 7 of the World Series. That’s incredibly difficult! In fact, the pitch location wasn’t actually that bad, as shown below.
As the graph shows, the purple home run ball was a middle-in, down strike. Not great location, but not horrible by any stretch. It’s the type of pitch that doesn’t usually hurt Chapman. But in this instance, Davis had a better than average chance to barrel up that baseball because Chapman was not his normal, rested self.
Joe Maddon typically gets a lot of credit for being a great tactical manager. However, his decision to use Chapman in Game 6 with a five run lead was highly suspect at the time, and it almost cost the Cubs the World Series. Of course, we must evaluate Maddon on his thought process rather than the observed outcome. Yet this move is fair game because it was highly questionable at the time.
Did Chapman know he wasn’t his normal self? Maddon — showing an extreme lack of faith in the rest of his bullpen — sent Chapman back out for the ninth inning. And something odd happened. Of the 14 pitches Chapman threw in that inning, 9 were not fastballs (or roughly 65%). To see how abnormal that is, I looked at every inning (and partial inning) that Chapman threw this year to investigate whether he ever threw that high a percentage of non-fastballs. The answer is no.
That’s right: the owner of the hardest heater in the world was reduced to throwing slider after slider to get through his last inning of the World Series. And you know what happened? Three up, three down. Because, again, baseball.
Aroldis Chapman will be an even richer man very soon. A team will — somehow — look past his history of domestic violence and rationalize paying him something on the order of $100 million. Yet on the night of November 2, in the biggest situation of his life, he looked anything but worth it.