Recently, we took a look at trends from the first eight weeks of the NFL season, and compared it to what generally correlates to success in a normal season. Well, why not do the same for baseball? After all, similar to our NFL study, we’re dealing with a small sample in a 60-game season, and with all the ramifications from the atypical nature of a COVID-19-impacted season, my hypothesis is we will find some interesting results.
Previously, we had concluded that offense was around 5.35 times more important to winning than defense, while offense was slightly more correlated to success than pitching. However, pitching had been trending upwards in terms of importance in recent years, so it will be interesting to see if that continued in 2020.
With the proper weighting and equations, I was able to project a team’s expected wins based on their offensive runs above average, defensive runs above average, and pitching WAR. I am happy to state that this model had tremendous success in doing so:

This scatterplot represents the correlation between projected expected wins based on my model and the team’s actual expected wins. If 93.1% of a team’s xWins can be projected based on the model, it definitely is a valid approach moving forward; the success should be only greater in a longer season! Plus, despite this being a smaller sample size, the coefficient of determination (88.1%) was very strong between projected wins and actual wins, so, for the most part, teams performed up to their expected capabilities based on their overall output. The small sample may have caused for a team to produce better or worse than they should, but the teams who had success deserved to do so. This is tremendous when analyzing the legitimacy of this season.
Trends
With that being settled, let us focus on what correlated to success between offense, defense, and pitching. How different was this season than years in the past?
Offense

Defense

Pitching

I have been a major proponent of the “defense is overvalued” movement, but this difference in significance between offense and defense is even greater than I would have imagined; it was eight times more correlated to winning this season. Teams are starting to build their rosters more towards trying to score as many runs as possible, and it is worth noting that the Dodgers, Braves, and Astros, three of the four final teams in the postseason, all ranked in the bottom-ten in defensive runs above average. Meanwhile, being a top-ten defense surely didn’t save the Rockies or Diamondbacks, while several of the successful teams that were strong defensively either benefitted from great offense (Padres) or great pitching (Indians, Rays).
Although the run-scoring environment was initially unfavorable, it all evened out near the end, with 4.65 runs scored per game. Overall, the importance of pitching remained slightly the same, and it appears that when you combine pitching and defense, a run saved is as important as a run earned. It’s just understanding that preventing runs comes mostly from pitching, rather than defense, that causes a misconception about the significance of high-end defense.
For this being such a short season, it is very encouraging that what correlated to winning remained in tact. This differs slightly from our NFL study, and leads me to believe this season was more legitimate than it got credit for being.
Lucky Teams
Now that we have assessed the legitimacy of this season, as well as the model’s ability to properly project a team’s performance. It is time to assess who over/underperformed this season, based on their output in the three main areas of baseball.
Let us start with the teams whose actual xWins didn’t match up with their projected wins:
- Diamondbacks (3.47)
- Cardinals (3.46)
- Cubs (3.13)
Ironically, all three of these teams rated highly defensively, but struggled mightily on offense. Even, more interestingly, only the Cubs benefitted from strong pitching. Perhaps defense allowed Arizona and St.Louis to flex their muscles and leverage a small advantage to overachieve their projected success, but going into 2021, a longer season, expecting to do so again is likely to be problematic.
As for the unlucky teams:
- Mets (-7.11)
- Phillies (-3.69)
- Angels (-3.17)
HM: Yankees, Reds, Brewers
Wow! That’s a massive difference for the Mets. Since their pitching staff ranked 4th in K/9, you wouldn’t have expected their poor defense to make a noticeable impact, while the same is true for the Phillies (6th in K/9). The Mets Phillies, and Angels all had top-ten offenses. Philadelphia and Los Angeles got really poor production from their pitching staff, which would explain this somewhat.
The Mets, though, are an interesting case study. Despite having the third-ranked offense, they only ranked 13th in runs scored. That’s poor sequencing at its finest, as their clutch rating, per Fangraphs, ranked 30th. That is far from ideal, but does indicate that they’ll have more success in the future.
It is also worth noting that all three of these teams ranked in the bottom-ten in clutch rating, which seems to be a theme that would explain how they underachieved to the extent they did. With better timing of their offensive production, all three of them could have been playoff teams.
Now, let us do the same thing, but look at which teams’ actual win totals were higher/lower than you’d expect:
- Marlins (6.16)
- Rays (3.63)
- Cardinals (3.46)
HM: Rockies, Cubs
The Marlins’ expected wins of 26 didn’t match up with their actual 31 wins, so that is more of traditional luck in closer games, and the same is true for the Rays; Tampa Bay’s elite bullpen and game management may explain that, however. Outside of that, we see the Cardinals, Rockies, and Cubs re-appear on this list, and all three of them will need more offensive production next season.
As for the unlucky teams:
- Mets (-9.11)
- Phillies (-5.7)
- Angels (-5.17)
HM: Orioles, Yankees
Those poor Mets, Phillies, and Angels! With all three of them up for front office openings, they are all certainly teams to keep an eye on; they are very likely to benefit from positive regression next season.
Overview
Surprisingly, there were a lot of stable aspects of this season. Offense remained far more important than defense, and a run prevented remained as important as a run scored; what correlated to winning remained in place. It is very encouraging to see my projection model be able to predict team performance so well, despite it being a short season, and it seems like the small sample just allowed certain teams to do better than expected when comparing their expected wins to actual wins, rather then them having better run differentials than they deserved. With the Mets, Phillies, and Angels all suffering from poor luck this season, they may be more appealing front office openings than you would think, especially the Mets with owner Steve Cohen taking over.
The key aspect for MLB front offices is to analyze what to take away from this season with regards to their offensive, defense, and pitching production. There is no easy answer to that, but then again, this is what they get paid to do! As for this 60-game season, though, it is quite encouraging that the deserving teams were the ones who experienced the most success.
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