You Don't Need To Consider Steroids To Find That Aaron Judge Just Had The Best Season Ever
Aaron Judge just had the best hitting season of all time. He hit .311/.425/..686 with 62 home runs and 11.4 fWAR. It was incredible to watch. Hand him the trophy.
But 11.4 fWAR isn’t the highest of all time. Babe Ruth hit .393/.545/.764 with 15 fWAR in 1923! The offensive statistics that go into fWAR adjust for the average performance level each year. So, Ruth is better, case closed, right?
A quick glance at the Fangraphs leaderboards show that Judge’s 2022 season is only the 16th best of all time:
I’ve always had trouble believing these leaderboards. There are a lot more talented athletes playing professional baseball today than ever before, yet the fWAR and other leaderboards are dominated by players born before the Great Depression. The only exceptions here are Barry Bonds during his historic run in the early 2000s, one season from Carl Yastrzemski and Aaron Judge in 2022. The problem persists farther down the leaderboards: there are only a handful of modern players in the top-50.
Ruth. Williams and Mantle were great players, but generational baseball talent should come along… once per generation. Where is Mike Trout on these leaderboards? Where is Ricky Henderson? Something is wrong if we conclude that almost all of greatest seasons of all time are all now more than 60 years old.
Of course, we’ve all heard this debate before. Babe Ruth did it on hot dogs and beer. Would he be good today with modern fastballs and training methods? The answer is subjective, because we can only compare him to his weak competition. But, we can answer how difficult it was for a player to stand out from the crowd in Ruth’s day using statistics.
If we calculate the standard deviation of fWAR for all qualified players since 1920, we can roughly measure the “quality of competition” for all hitters in that year. A higher standard deviation suggests that the best (and worst) players tend to stand out more from the average player during that season, while a low standard deviation suggests that players are clustered more around the average player.
Here is a figure of the historical trends in MLB competitiveness:
Note: I’ve removed the shortened 2020 season from this figure.
That’s really cool! We can see how baseball became more competitive over time. From the 1920s through 1970s, baseball gets increasingly competitive. Integration and the professionalization of the sport make it much harder for the best players to stand out from the average players.
By the late 1970s, baseball settles in to a high level of competition, until 1996-2004, when it becomes easier for some hitters to stand out from the average. If only some players are taking steroids, we expect that to manifest in a competitive advantage over their peers, increasing the spread between the best hitters and the average hitters. Baseball then settled into the high competition, low standard deviation environment that Aaron Judge has played his entire career during.
Finally, we can adjust each player’s fWAR by inflating or deflating their performance to match the competitive environment in 2022. For example, Barry Bonds had a 12.5 fWAR in 2001, when competitiveness was 15% lower than in 2022. We thus multiple 12.5 by (1 - 0.15), adjusting his season down to a 2022 equivalent of 10.6 fWAR.
And Aaron Judge’s 2022 jumps from #16 all time to #3 all time. The only seasons better than Judge were both from Babe Ruth at the height of his powers.
In social science, we often first approach a measurement system with a term called “Face Validity.” The raw fWAR list suggested that most of the best individual performances in MLB history occurred before WWII, but that doesn’t make a lot of sense on it’s face. Other big seasons also pop out, such as Ripken in 1991, Arod in 2007, Yount in 1982, Betts in 2018 and Morgan in 1975.
Can we call Aaron Judge’s 2022 the best season of all time? I’ll let you be the Judge (pun intended). Babe Ruth didn’t take steroids, but he also didn’t have to compete against players who looked like Aaron Judge. I’m going #99.