On a year to year basis, there are always teams that over preform. That’s just how baseball is – the worst team in baseball will beat the best team in baseball 35% of the time. That’s why we have 162 games, but that’s not the point of this article.
How do you measure an over preforming team? You can always look at the transactions in the offseason, the schedule, and all of that, but what about comparing this season to the past 3 seasons to determine if the team is on par with the last 3 years – or if they are underperforming or over performing.
Enter the Over Performing Measure (OPM). The OPM tells you if a team is obviously over performing with a simple formula. Let’s take the 2019 Orioles, for example. The Orioles had a 2016 season where they finished with 89 wins, but then dropped off to 75 wins in 2017. In 2018 they self destructed and thanks to injuries (and other stuff) they fell to 47 wins.
They had obviously under performed and it showed in the OPM rating as they rated a +35. With such a huge number, it didn’t take three guesses to find out that the Orioles would improve the next year in the win column. That’s pretty much what happened as the Orioles rose to 54 wins, obviously improving from 2018.
The flip side of the coin is also true as in 2016 and 2017 the Red Sox had 93 wins, but thanks to improvements and cheating in 2018 they rose to 108 wins. This didn’t make the prettiest OPM, as it called for a drastic drop and that happened in 2019, as they fell from 108 to 84 wins. The Red Sox had obviously over performed in 2018 and they were bound to go down.
Let’s take a look at another example. In 2017 and 2016, the Nationals average 96 wins but in 2018 they dropped to 82 wins. They had clearly gotten unlucky and of course in 2019 they won the World Series after rating a +14 on the OBM.
And I am happy to report that this system is 57% accurate. So that means that while this system is pretty good, it shouldn’t be relied on too heavily to determine whether a team will improve their record or if their record will worsen.
And once you know if a team will improve their record or not, it’s time to use this system to figure out on average how much. So I took every team’s value from 2019 in OPM and their actual change from 2018, and I subtracted the two values. Unfortunately for me, both OPM and the actual change were -2 meaning that this isn’t actually a measure of how many wins a team will improve by, more so if a team will improve its win total.
Although this system may seem pretty good just judging by that percent, there are multiple obvious flaws that you just can’t take into account. What about if Christian Yelich gets injured? Who does the Brewers put in the OF to cover? Or Mike Trout? These are things that a team just can’t plan for and the team’s record will obviously take a hit whenever such an important player goes down to injury. When looking at a team’s OPM rating, it’s painfully obvious that it can’t take lots of things into account.
Free agents can make a huge impact to a team’s success the next year. Unlike college football recruiting where recruits are usually eased into the role, free agents just play right away and have a big impact on the season.
This can allow for drastic season to season change. And in college football you plan for a player graduating, but you can’t plan for a surprise trade offer, a free agent too good to pass up, or player attitude or injuries. This allows for holes at a position than can cause year to year drastic change at each position causing madness, and at the end of the day, unpredictability.
Although this system has some obvious flaws, in general I think that it is a solid system. We'll have to see what it predicts for the upcoming 2021 season in a later article. Thanks for reading!