Every MLB awards voter will have their own way of deciding how they want to pick their Cy Young winner. I am going to explain why it shouldn’t be much of debate no matter which way you want to slice it. From the perspective of best expected results based on outcomes of at-bats, best run prevention on a rate basis, or best total production over a volume of innings, Corbin Burnes was the best pitcher in the National League (and the Major Leagues) this season.
No pitcher in baseball was more effective at creating favorable outcomes from opponent plate appearances than Corbin Burnes was this season. Burnes was in the 99th percentile of both xwOBA and xwOBAcon. Only Jacob deGrom (who pitched just 92 innings) had a superior xwOBA amongst starting pitchers, meaning that Burnes’ ability to create weak contact, produce strikeouts, and avoid walks was the best in MLB this season. His xwOBA translates to a 2.01 expected ERA, which indicates that he was the best qualified pitcher at creating plate appearance outcomes that should lead to preventing runs. This 2.01 xERA is 42 points lower than his MLB-leading 2.43 ERA for qualified starters, implying that his performance should’ve yielded even better results despite his results already being the best in baseball. More peripherals seen in the graphic above further indicate that Burnes was able to create favorable outcomes across the board in every way at an elite level.
Further evidence that Burnes had bad luck in his results compared to the expected outcomes from his batted ball data lies in his surprisingly high BABIP of .309, which was the 2nd highest amongst National League qualified pitchers. There were no other NL Cy Young contenders remotely close to Burnes’ lofty BABIP, and his defense’s -3 OAA (Outs Above Average) when he was on the mound was tied for 254th worst (out of 297) in baseball out of all pitchers with enough defensive plays made behind them to qualify.
A handful of examples of some of the mishaps that took place in the field that contributed to this inflated BABIP and higher than expected ERA can be seen in the video embedded below. One more factor that ties into examining the outcomes created by pitchers lies in park adjusted statistics. Burnes was only the ERA leader in baseball by .03, but he lead MLB in park adjusted ERA+ by a far more substantial margin, considering the hitter-friendliness of his home Miller Park. His 176 ERA+ led 2nd place Brandon Woodruff (166 ERA+) by a whole 10 points.
On a rate-based level, Corbin Burnes dominated 2021 better than any other starting pitcher. He lead all of baseball with a 35.6% strikeout rate and was fourth best in MLB with a 5.2% walk rate. These numbers are good for a 30.4 K-BB%, which is the best in baseball by a 1.5% margin. This elite 30.4% leads the fourth place K-BB% leader by over a whopping 5%, and Burnes’ K-BB% would rank sixth on the MLB K% leaderboard, meaning he was the best strikeout-walk starting pitcher in MLB this season, and it wasn’t even close. It’s fair to say Burnes was great at everything this year, because the favorable contact he generated on balls in play was also the best in baseball. Burnes allowed the fourth lowest hard-hit% (30.5) in baseball, and he lead MLB in percentage of PAs that yielded a barrel (1.8%) by a wide margin. In fact, the gap between Burnes’ 1.8 barrels/PA percentage and the second place pitcher on the leaderboard (2.9%) is greater than the gap between this second place pitcher and the 20th pitcher on the leaderboard (out of only 90 qualified pitchers).
Perhaps the single most impressive statistic that Burnes put up this season was his historic 1.63 FIP. Burnes limited walks and home runs while drawing strikeouts at an all-time great rate; his 1.63 FIP in 2021 is second only to 1999 Pedro Martinez (1.39) from all seasons since Jackie Robinson broke the color barrier. In the perspective of this season, Burnes’ 1.63 FIP leads second place (Zack Wheeler‘s 2.59) by such a wide margin that everyone should now be convinced that Burnes was lapping the competition in terms of how dominant his pitching was on a per inning basis.
An argument used against Burnes’ Cy Young case is his lack of counting stats, such as his innings pitched (167 IP, 32nd in MLB) and games started (28, 36th in MLB). The counterargument lies in the fact that his total production was still superior to any other pitcher in baseball, despite the smaller amount of game time that this production occurred in. A stat that factors in gross production is Context Neutral Wins (WPA/LI), which measures the Win Probability Added for a player with the situational leverage component factored out of the equation. An advantage of this stat over Win Probability Added is the fact that pitcher cannot always control the outcomes of certain balls in play, so the leverage component can punish the pitcher if the defense struggles under high leverage as well. Corbin Burnes’ WPA/LI was 4.37 this season, which led all pitchers in baseball. Zack Wheeler (4.13) was the only other pitcher in baseball who was north of 4 wins by this metric. This speaks to the gap that Burnes was able to create between himself and the bulk of the field in regards to raw quantity of production when neutralizing factors that might be adding unnecessary variance. Not to mention that his innings total was lessened intentionally by the Brewers to manage his workload, which had already far surpassed his career-high of 116.2 innings in 2018 (with both his AAA and postseason innings included).
One of the crowning stats on Burnes’ Cy Young case is his 7.5 fWAR, a figure that not only leads all NL players, but all MLB players in baseball not named Shohei Ohtani. fWAR is a great measure of a pitcher’s season because it is dependent on both park-adjusted FIP (the quality of pitching) and innings pitched (the quantity of the quality). Work horse Zack Wheeler was second with 7.3 fWAR, but no other National League pitcher was within 2 fWAR of Burnes’ elite 7.5 benchmark. These stats back the notion that Burnes was able to manufacture quality production as good as or better than any other qualified pitcher in baseball this year. When this conclusion is supplemented with the incontestable fact that Burnes dominated all other pitchers on a rate basis, it should be clear that Corbin Burnes was the best qualified starting pitcher in baseball this season. Other achievements like tying the all time record of striking out 10 consecutive batters as well as pitching 8 innings of a combined no-hitter with closer Josh Hader provided what was perhaps the cherry on top to what should be a well-deserved 2021 NL Cy Young finish.