Just How Good Is Aroldis Chapman?
If you’re a closer in the midst of an historically good season and you know it, clap your hands (Jim McIsaac / Getty Images)
“I wish there were a good, park-adjusted stat that compares a pitcher’s ERA to the average ERA of pitchers league-wide”
You’re in luck! ERA+ is a park-adjusted stat that compares a pitcher’s ERA to the average ERA of pitchers league-wide. Mariano Rivera has the all-time record for ERA+ over a career at 205 (the average ERA+ is always 100), so Mo was more than twice as good as the average pitcher over his entire career. His ERA+ eclipsed 300 twice, in 2005 and 2008. His career-high ERA+ was 316. In Brad Lidge’s perfect 2008 season (2-0, 41-41 on saves), his ERA+ was 224. Dellin Betances was UNTOUCHABLE in 2014 and 2015. His ERA+ over those two years was 273. Even 2016 Andrew Miller before his trade to the Indians peaked at 311 and finished the season at 304.
Since 2000, the best season by ERA+ among pitchers with at least 50 IP is Zack Britton’s 2016 season, in which he was the best reliever in baseball and posted an 803 ERA+. He was a perfect 47 for 47 on saves (already better than Chappy) and finished 4th in the AL CY Young voting. 803 is the best ERA+ for a season since 2000 by 162. 162! Zack Britton was 162% better than the 2012 vintage of Fernando Rodney, who is second on the list!
AROLDIS CHAPMAN’S ERA+ THIS YEAR IS 874. That’s a full 71% better than Britton’s season. Look, I get he has only thrown 19 innings, but WOW. By the way, in addition to being the best season since 2000 by ERA+, Britton’s 2016 was also the best season OF ALL TIME. So Chapman is on pace to be the all-time record holder. Is that any good?
“I actually hate advanced statistics and only care about ERA”
Well you’re also in luck. Not surprisingly, because of the way ERA+ works, Zack Britton’s 2016 season also sports the best ERA of any season from a pitcher with more than 50 innings pitched in a year. He posted a 0.54 ERA that year in 69 (nice) appearances.
Aroldis Chapman’s ERA this year is 0.47. 0.47!!! In case you’re wondering, that’s pretty good. It was also 0.00 until Sunday, which is also good.
“Can you use stats I understand like batting average and OPS?”
Oh it would be my pleasure.
The current single-season record holder (min. 50 IP) for opponent’s batting average is… Hmm.. Look at that! Aroldis Chapman! In 2014 with the Reds, opponents hit a measly .121 off of him (this is going to become a trend). Is Aroldis Chapman on pace to break that record, you ask? He sure is. To this point in the season, opponents are hitting an even .100 off of Chapman. That is not all that good (for them).
Chapman doesn’t rate out quite as well in OPS, given that he is not immune to the walk and the majority of hits he has allowed this year have gone for extra bases. Even still, his .403 OPS allowed, if he can carry it through the whole season, would be the sixth best by any pitcher ever.
Remember that great season by Zack Britton that we discussed earlier? Chapman’s batting average allowed and OPS allowed are 62 points better and 27 points better than the numbers Britton posted, respectively.
“I was lying when I said I cared about ERA, batting average, and OPS, strikeouts are the only things that matter to me”
Well that’s an interesting perspective for you to bring, certainly.
It would not be fair for us to use a gross strikeout total to measure Aroldis Chapman’s performance. He doesn’t pitch as many innings as, you know, starters, and we shouldn’t expect him to strike out the same number of guys in 50 innings that a starter strikes out in 200.
Thankfully, a long time ago some smart dudes and or dudettes came up with a thing called a rate. Rates allow us to compare things that occurred over different periods of time #MathBlog.
So anyway, the current all-time record holder for strikeouts per 9 innings (K/9) in a season (min. 50 IP) is.. Oh! Check it out! Aroldis Chapman! In 2014 with the Reds, Chapman posted a dominant 17.67 K/9 (106 K in 54 IP).
He’s just shy of that mark this year, posting a 17.53 K/9 over his first 19 innings. That’s… Uhhh… Pretty darn good.
“One time I heard David Cone talk about FIP”
That’s good! FIP, or fielding independent pitching, is a stat that measures how good a pitcher is at striking batters out while not walking them or allowing home runs. Aroldis Chapman’s current FIP of 1.20 is 13th all-time among pitchers who have pitched at least 18 innings, and, if he can continue it, would be 5th all-time among pitchers with at least 50 IP in a season. That’s not bad either.
“No, really, I just want to see a fun chart of Chapman’s K%”
Basically Aroldis Chapman just strikes guys out all the time
I’m not going to leave you hanging with just the graph though. Chapman has generated 37 strikeouts in the 70 plate appearances against him. That’s a cool 52.9%. That is the second-highest K% EVER for a pitcher with at least 18 IP, behind only the insane season that Devin Williams posted last year in which he struck out 53 of the 100 batters he faced.
Chapman himself has the single-season record for K% if we bump the minimum IP up to 50. In that great 2014 season with Cincinnati, he operated at 52.5%. So we’ve identified another record he’s on pace to break. Pretty nice.
“What’s a stat that’s completely off the charts though? I get that all of these are good but I want something even more ridiculous”
I kind of expected a lot of the other stats I found when I was doing research for this article. This next one really blew me away.
Since 8/29/2020, Aroldis Chapman (with different start and end points) has posted the 5 best 19-game stretches by K% OF ALL TIME. If that’s not good enough, in that same time frame he is also responsible for 7 of the top 11 19-game K% streaks. Since last fall, Aroldis Chapman has made things we had literally never seen before into routine occurrences. In that way, there is actually no way to contextualize how good he has been. In multiple respects, he is producing at greatest-of-all-time pace.
“I get it but can I just see a reel of him striking guys out?”
I’m so glad you asked.
“So why is he doing so well?”
Thanks to Baseball Savant for the chart
Let’s take a look at Chapman’s average pitch velocity.
The two things I really like here are the upticks in the orange line (sinker) and red line (4-seam fastball).
His average sinker velocity is at 100.9 MPH this year. That ties his career high from 2018 when he began throwing the sinker. The 4-seamer is a similar story. His average fastball is 98.9 MPH this year, the highest it has been since 2018.
As a result of these upticks in velocity, Chapman is currently generating a career-high whiff percentage on his sinker (70%), and he’s producing his second-highest whiff percentage on his fastball (34.2%) since 2015.
His put away percentage on each of these pitches (the percentage of two-strike pitches that result in strikeouts) are also at career highs, with the sinker at 58.3% and the 4-seamer at 34.3%. The guy is getting swings and misses all over the place. The great thing about swings and misses is they do not result in batted balls that could turn into bad things like home runs, and they do not give you the chance to become the victim of poor defensive positioning or other BABIP nonsense. Part of what’s made Chapman so effective is that all the swings and misses keep him in control of the game rather than putting him at the mercy of the game. If he keeps doing that, he’ll continue to dominate.
This is all not to mention his splitter, which he has thrown 35 times in 2020 and 2021 without ever allowing a hit. For what it’s worth, he hasn’t allowed a hit on the sinker this year either. He’s simply been untouchable.
“Can we review our findings?”
I’d love to. Here are some stats in which Aroldis Chapman is on pace to to post the best season of all time.
ERA+
ERA
K%
Batting average allowed
Here are some stats in which Aroldis Chapman is on pace to have a top-6 season of all time.
K/9
FIP
OPS allowed
In short, Aroldis Chapman is doing something historic this year (or, depending on how you want to think of it, a lot of stuff that’s historic). His velocity is back up after a couple years of being slightly down. He has successfully added a devastating splitter to his arsenal off of which no one has ever gotten a hit. I really don’t know what other way to put it. Every time Aroldis Chapman has stepped on the mound (for you pedantic jerks I’ll add the following phrase) in the regular season since late last August, we have witnessed greatness at a level that we have quite literally never seen before.
I recommend that you take some time to appreciate it. It’s been almost 25 years now that the Yankees have had the best active closer in the game on their team most of the time. I know you’re mad about Mike Brosseau and Jose Altuve or whatever, but try to enjoy what Aroldis Chapman is doing here.
Let’s go Yankees.
