Will the New “Year of the Pitcher” Crown a New ERA Champion?

Jacob deGrom‘s already microscopic ERA needs even a stronger microscope to spy it after his outing Monday, a six-inning shutout against the Arizona Diamondbacks that lowered his ERA to 0.71. We’re no longer in April, and we’re not even in May, so this new level of dominance can’t be easily ignored as the product of a small sample. Once performance of this magnitude reaches June intact — and 0.71 is deGrom’s second-highest seasonal ERA after the end of an outing — you have to seriously give at least a thought to the prospect of a pitcher making a run at Bob Gibson’s live-ball ERA record.

We had a chance at this happening last year, thanks to the asteriskesque 2020 season and its 60-game slate, shortened as a consequence of COVID-19. I talked about the possibility going into last season, with ZiPS projecting a one-in-four shot of someone catching Gibson’s 1.12. Nobody did it in the end, but Shane Bieber’s 1.63 was the one of the best ERAs for a qualifying pitcher since Gibson’s in 1968. Bieber and Trevor Bauer, the two pitchers who came closest, fell well short of Gibson but given the relatively high levels of league offense, their efforts were enough to get them the third and fourth spots on the all-time single-season ERA+ ranks.

Catching Gibson in a 60-game season would have been an accomplishment, but not really a full one. Records are naturally set in conditions that benefit players, and Gibson was no exception: 1968 was dubbed the Year of the Pitcher thanks to a league ERA of 2.98, nearly a half-run lower than any season since the spitball was banned. Gibson’s 258 ERA+, which takes into account league offense, still sits atop the leaderboard, but at least it doesn’t utterly wreck the recent field, which consists of Pedro Martinez (243, 1999), Roger Clemens (227, 1997), and Zack Greinke (227, 2015) among others.

But since 2021 is a full 162-game season, catching a 1.12 ERA would feel a lot less like sneaking in through a loophole. A significant drop-off in league offense (to a 4.02 ERA) could be credited for an assist, but it’s not a number that is unfair relative to baseball history. So, can he do it?

deGrom has missed a few starts so far in 2021, with no apparent ill results to his performance, and the Mets have been cautious with his pitch totals; he’s averaged fewer than 70 pitches in his last three starts. That’s beneficial to his chances, as no star pitcher has a long-term ability to keep their ERA that low, even Gibson; just clearing the one-inning-per-team-game requirement optimizes things. deGrom will likely end up with around 30 games started this season, so a good place to begin in gauging his odds is to see if anyone’s come close to 1.12 in a span of 30 games starts, crossing over seasons, since 1920. I’m only listing unique 30-game runs since there is naturally quite a bit of overlap in runs:

Best ERA for Qualifying Pitchers in 30-Game Spans (Since 1920)
Pitcher Year(s) W L ERA IP
Bob Gibson 1967-1968 20 6 0.94 267.0
Jake Arrieta 2015-2016 25 1 1.13 215.0
Roger Clemens 1990-1991 22 4 1.30 228.3
Carl Hubbell 1933-1934 17 8 1.30 215.3
Clayton Kershaw 2015-2016 19 3 1.32 225.3
Dwight Gooden 1985 22 1 1.33 243.3
Pedro Martinez 1999-2000 20 4 1.34 221.0
Luis Tiant 1967-1968 20 6 1.34 228.7
Vida Blue 1970-1971 21 3 1.36 244.7
Jacob deGrom 2018-2019 10 9 1.40 205.0
Dean Chance 1964 17 6 1.40 225.7
John Tudor 1985-1986 23 1 1.41 242.0
J.R. Richard 1979-1980 19 6 1.44 225.7
Bobby Shantz 1951-1952 26 4 1.44 262.3
Max Lanier 1943-1944 17 5 1.47 202.7
SOURCE: Baseball-Reference

Gibson’s best 30-game span was even better than his 1.12 ERA, dipping under one. J.R. Richard’s presence on this list is especially cruel, as his 30-game span ended with the final game of his major league career. Before Richard’s next start, he suffered a stroke caused by a blood clot, and while he attempted a comeback a few years later in the minors, he was no longer the same pitcher.

Nobody catches 1.12 on this list, but many come close enough that the result is at least plausible. Jake Arrieta was only a run from accomplishing the feat. deGrom himself appears on this list, his 30-game span running from April 21, 2018, through April 3, 2019. His 1.40 ERA over 30 starts comes out to an ERA+ of 266 in a higher run environment (by about a tenth of a run) than 2021 so far. A tenth of a run isn’t a lot, but to break a record like this, every advantage helps. Yes, Mets fans, I see that 10-9 record for deGrom over that stretch.

To get an idea of deGrom’s probability of finishing with an ERA of 1.12 or better, I worked with a technique I’ve used in the past, which “simulates” a season using Monte Carlo algorithms and a smoothed model of a pitcher’s starts based on their projections and historical usage. At 189.2 innings (what he has in the bag, plus the 22 starts of 6.3 innings per start in his depth chart projections), he needs to allow 23 or fewer runs or a 1.23 ERA for the rest of the season. At 162 total innings, he’d have to maintain a 1.30 ERA the rest of the way.

deGrom’s no slam-dunk to catch Gibson, but he’s got a fighting chance, with my model estimating a 3.1% chance to beat a 1.12 ERA, or more precisely, Gibson’s 1.122538 (no cheating with rounding here!). That’s about 31-to-1, a little better than getting the exact number in roulette and roughly the probability of a 20-homer hitter getting a round-tripper in any given at-bat. In other words, it’s more likely than not that he falls short of the feat, but it’s definitely possible and firmly in the realm of plausibility.

Jacob deGrom is having the best run of his career and quickly developing a Hall of Fame case based on Koufax-levels of peak performance. Catching Bob Gibson would be a fantastic sentence on a plaque in Cooperstown. Hopefully, the Mets’ offense has the decency to give him more than 10 wins if it should come to pass!

Dan Szymborski is a senior writer for FanGraphs and the developer of the ZiPS projection system. He was a writer for ESPN.com from 2010-2018, a regular guest on a number of radio shows and podcasts, and a voting BBWAA member. He also maintains a terrible Twitter account at @DSzymborski.

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2 years ago

The new deadball era isn’t really a joke and it isn’t really funny at all, but for some reason I keep laughing harder and harder.

2 years ago
Reply to  sadtrombone

As Dan alluded to in the piece, the run environment isn’t really *that* different from historical norms. Hell, you only need to go back to 2015 to find a lower run environment than 2021 so far! It’s more the composition of the runs that rub people (including myself) the wrong way, but I think it would in no way lessen the achievement if DeGrom were indeed to run an ERA lower than Gibson’s mark. In fact, comparatively speaking, it would be more impressive today than in 1968!

2 years ago
Reply to  D-Wiz

No, I don’t think it would lessen the achievement. It’s not entirely a coincidence either. There are six qualified pitchers with ERAs less than 2 right now. Last year it was 3 (in about the same number of games). You don’t have to shift the composition of the run scoring very much for some pitchers to do way, way better than before.

That said, upon reflection, the reason why deGrom is suddenly unlocking this achievement now is probably much simpler: Francisco Lindor is playing shortstop and the Mets have had so many injuries they probably haven’t played players who can’t run well enough to adequately play the position they’ve been assigned.

2 years ago
Reply to  sadtrombone

The Mets infield defense – especially Lindor and Villar – has been a huge part of their early success. Look at Marcus Stroman and Taijuan Walker’s numbers for further validation. Somehow this team is scoring enough runs to win games… but for those of us who’ve watched Mets pitching done in by bad defense for far too long, it’s an appropriate turnabout.

2 years ago
Reply to  sadtrombone

Tom Verducci wrote an article about the Mets improved defense in Sports Illustrated a few days ago. The Mets are using twice as many shifts as they did last year. They have traveling data analysts who help analyze and convey how and why to shift against certain players, and the pitchers are also part of that conversation as to whether to shift against players.

The Mets have upgraded to a modern analytical shifting defense, and have done so by getting buy-ins from management and players through engagement and results.

Greg Simonsmember
2 years ago
Reply to  D-Wiz


While an ERA under 1.12 would be an amazing accomplishment, I wouldn’t consider it more impressive than Gibson in ’68 considering his 304-2/3 IP. deGrom won’t throw anywhere close to that total, and while I understand why, quantity is a big factor in this comparison.

2 years ago
Reply to  sadtrombone

Some dead ball! Every day and night there are 450+ moonshots being hit.

2 years ago
Reply to  sadtrombone

I’m having a lot of trouble resetting my mental image of what good offense looks like. By just about any measure, the White Sox have one of the bets offenses in baseball and yet, they don’t hit a lot of HR, it seems like they get shut out once a week, and they field several bad, veteran, hitters in the lineup on a daily basis like Billy Hamilton and Leurys Garcia. It is hard to see a lineup with three or maybe four guys hitting .220 or worse and think of it as a good lineup. It’s also hard to think of some of those guys as productive offensive players. They have 5 guys hitting under .220 getting regular playing time, and all of those guys have wRC+ of 86 or better and Grandal still has a bizarre line: .131/.385/.333, wRC+ of 119! That’s got to be the best offensive performance by a .131 hitter in history.

Maybe runs are the same as 2015, but offense is really weird this year.

2 years ago
Reply to  MikeS

Look at the Jays, they led the world in almost every offensive category last month.

2 years ago
Reply to  MikeS

CHW’s got the best team OBP in baseball, a product of the 3rd-best BB% and highest BABIP in the league. Not sure if that’s an active strategy from their hitting coach or not, but their offensive production isn’t too much of a mystery– year in and year out, live ball or dead ball, a great team OBP means you score a lot of runs. Moneyball wasn’t wrong there!

There’s also been some outright bizarre offensive performances. Grandal’s unorthodox path so far to near exactly his career wRC+ is well-known, but there’s others. Moncada and Anderson are back to their astronomical BABIP hijinks but with power outages, while Jake Lamb is crushing the ball and BILLY HAMILTON suddenly hitting for power! He’s got the third-best ISO on the squad at .203! Easily the best average EV and hard-hit rates of his career. 7 of his last 12 hits have been XBH, including two of his *24* career dingers. Very strange stuff!