Disclaimer: I will be referencing a lot of stats in this article. I will put links to explanations below that explain the stats a lot better than I can. Look through these before reading if needed.
Stats taken before 9/4/21
FIP, xFIP, K/9 BB/9 HR/9, xWOBA, ERA+/ERA-/FIP-, SIERA
Corbin Burns’s 2021 Season is truly insane.
After Jacob deGrom was injured this summer, the race for the NL Cy Young award broke wide open. deGrom before his injury was pitching one of the most dominant seasons of all time. A 1.08 ERA, 14.28 K/9, a 1.23 FIP, 1.61 xFIP, 1.55 xERA, 1.73 SIERA, a 45% strikeout rate a 0.55 WHIP and a .128 AVG.
Let me give some explanations and reference points. K/9 is basically the average of how many batters a pitcher strikes out per 9 innings. The top 20% of pitchers have a K/9 of about 7.56, deGrom had almost twice that. FIP stands for Fielding Independent Pitching, taking into account only what the pitcher can control, Home runs, walks and strikeouts. The average FIP among the league is about 4.2, with the higher percentiles ranking among 3.2. deGrom was more than a third less.
These numbers are from a small sample size of 92 innings since his injury in July. Of pitchers who have pitched at least 90 innings in a season since 1960, only 1999 Pedro Martinez is even close to him in regards to the insane splits deGrom had.
I can ramble on about the greatness of Jacob DeGrom but sadly he was hurt in July and is set to be sidelined most likely till the end of the season or sometime in September, making him unqualified for the Cy Young award. In his place, a 3 pitcher race has emerged in the NL.
Walker Buehler from the Dodgers right now is the front runner, with the lowest ERA in the NL and leading one of the best teams in baseball in an attempt to repeat the Dodgers 2020 world series win.
Zack Wheeler from the Phillies is also in contention, rising from his 3 spot Mets role into a full-blown ace after signing with Philly last year, being top 3 in xWOBA, WAR, xFIP and has the most strikeouts in the league.
But in my opinion, I believe that Corbin Burnes is the best pitcher in the NL and in baseball by a wide margin.
Burnes leads the league in almost every advanced metric among qualifed pitchers. In the 139 innings he pitched, since 1960, among pitchers with at least 130 innings pitched in season only 1999 Pedro Martinez has had a lower FIP than Corbin Burnes in a season. With an astronomically low 1.58 FIP, he leads very handily
Look at that drop off. For reference, Burnes leads Wheeler by a whole point, and Buehler by about a point and a half.
Same applies for metrics like xFIP and FIP-
FIP- is a benchmark on how your FIP compares to the rest of the league, the same applies to things such as ERA+or-
100 would be around average for FIP- and the lower the better
Burnes leads these measures handily, being dominant in the metrics that measure what he as the pitcher can control.
xFIP is similar to FIP with this trend, Burnes leads pretty handily in this metric, even though the drop-off isn’t as extreme as the FIP drop-off.
Burnes has similar splits in regards to xWOBA given up according to statcast. Even though deGrom was blowing everyone out of the water before his injury, Burnes in his sample size is also blowing out the rest of the league, leading with a .216. (Burnes is the furthest dot to the left)
Wheeler is in 3rd with a .252.
When looking at Baseball Savant’s expected stats, Burnes leads pretty easily in expected batting average, slugging, isolated power, and on base percentage, holding the league to the lowest of those on average among qualified pitchers. For reference, the red dot is Burnes, he also leads in xWOBA as shown before.
But lets compare this to 2019, the last full year of baseball and the splits for expected stats.
The gap between the top in xWOBA in 2019 and 2021 is insanely different
He also leads in all the per/9 metrics. K/9, BB/9, HR/9 as shown with his low FIP. But he also ranks in the top 3 for K%.
Burnes’s signature pitch is his cutter that he pitches over 50% of the time. The run value of his cutter is the best in the league, with a run value of -20. Buehler’s best pitch has a run value of -17, while Wheeler has multiple pitches below -9 but no pitch as dominant as Burnes’s cutter. In fact, out of any pitch in the league with a minimum of 10 plate appearances, Burnes has the 5th best pitch by run value in his Cutter according to Baseball savant.
He also has a 31% Whiff rate on his cutter, with a 51% Whiff on his slider and 49% Whiff on his curveball, two pitches also with great run values. With a minimum of 50 Plate appearances, Burnes’s slider has the 16th and 25th best pitches according to Whiff% in the league.
For comparison, Buehler’s pitches consist mostly of his 4 seamer, which is one of the best in the league which he throws 45% of the time, followed by a slider, cutter, and curve, 14%, 16%, and 13% respectively. They all have great run values, but in regards to the Whiff rate, Buehler’s best pitch is 21%, and his most Whiff is in his changeup, something that he only pitches 3% and has a 38% Whiff, lower than Burnes’s secondary pitches. Wheeler’s most used pitch is his 4 seam as well, with his best pitch being arguably his slider. Those have a 25% Whiff and a 30% Whiff respectively, with a good curveball Whiff of 42%. His run values on pitches aren’t as solid as Buehler or Burnes, but he has a good variety, with 3 pitches under -7. Still, they both really don’t compare to the insane splits that Burnes has.
Now the argument people pose is that Buehler has a better ERA then Burnes as well as things such as WHIP, and batting average allowed. There are a multitude of issues with these stats compared to others like FIP, xFIP, SIERA and the other metrics stated beforehand. ERA and batting average are both contingent on fielding, something almost always the pitcher is not in control of. An example, if the field is shifted to the right and the batter bunts a ball down the opposite line, is that the work of the pitcher or the fielders? If a ball gets through the shortstop and not counted as an error and a run scores, is that more indicative of the pitcher or the shortstop? Things like FIP takes into account the things the pitcher can control, Home Runs, Walks, Hit by pitches and Strikeouts. SIERA also takes into account these things but also takes into account weak contact, ground balls and fly balls.
Here are the splits between Buehler and Burnes, Buehler also beats Burnes. in LOB%, ERA-, BABIP, and Innings pitched. Two of those stats are affected by fielding, with the LOB% being contingent on the players pitching and the fielder being able to either turn a double play ball or field correctly. BABIP is a sizable difference and something that Buehler does have the upper hand on, but looking at the rest of the stats and what looks more at what the pitcher can control, Burnes leads in almost every metric. ERA even is questionable when looking at the differences between Buehler and Burnes’s xERA, a metric that Burnes leads the league in. The expected stats tries to take into account launch angle and exit velocity, which shows some sort of inflation with Buehler’s normal ERA and his xERA, showing that fielding can truly be a factor. I wouldn’t say the park would be a factor, seeing that in comparison, American Family Field and Dodger Stadium both have a park factor slightly below average. There is an argument to say that Burnes has a smaller sample size than Buehler, which may inflate his numbers, but 130 innings. is MLB qualified, which is what puts you in the running for Cy Young. Besides, the drop off between Burnes’s FIP is massive, and when you take into account pitchers who have thrown over 60 innings a year, only deGrom has a higher FIP, after throwing 40 fewer innings. For SIERA and xFIP, only deGrom and Angels closer Raisel Iglesias have lower with Iglesias throwing 70 fewer innings then Burnes.
Let's take a larger look at Burnes splits and compare it to the past 6 years since Statcast has existed.
1st in xWOBA, xISO,xSLG, FIP, FIP-, Tied for 1st in xOBP, 2nd in HR/9, tied for 2nd in xBA, 3rd in xFIP, Top 5 in xFIP- Top 10 in K/BB, K/BB%, and SIERA. And we’re talking about splits compared to pitchers from completely different years. This is among qualified pitchers, so yes Shane Bieber’s 77 Inning season counts, but that makes it all the more impressive that Burnes beats him in several metrics. Burnes in some metrics like xWOBA is beating out Cy Young seasons like 2018 deGrom, 2019 Verlander, and 2015 Kershaw. And Yes, the sample size is too small to compare to these other pitchers, but Burnes if finishing the season healthy will finish in a very very elite company, Cy Young or not.
Zack Wheeler and Walker Buehler’s seasons are both very impressive. Specifically, Wheeler and his rise from the Mets to the ace of the Phillies are really impressive and an awesome thing to see. There has been really good pitching in the NL this year, with Brewers teammates Freddy Peralta and Brandon Woodruff being part of a dominant pitching staff in Milwaukee, San Francisco Giants pitchers Logan Webb and Kevin Gausman have been part of the rotation of the best team in the MLB and Buhler’s teammate Max Scherzer, who leads the league in K%. But when looking at everything that really analyzes the pitcher’s performance, Corbin Burnes is the NL Cy Young.