At the All-Star Break, here is a look at five MLB teams that are outperforming their run differentials, a key indicator on how their second half could go.
A simple view at the standings at this point in the season will tell you that the San Francisco Giants, Chicago Cubs and Washington Nationals have been good. Those three teams own the best records in MLB.
In that view, it’s also easy to see that Atlanta Braves, Cincinnati Reds and Minnesota Twins are competing for the number-one draft pick, as those three teams own the worst records in MLB.
However, with still just under half a season left, a team’s record is not the best measurement of what a team may do in the future. Often times, a team outplays its talent and could be a prime candidate for regression in the second half.
Run differential is a tool that is used to determine how many runs a team scores and how many they give up. Two teams could both hold equal 47-41 records; however, the team outscoring its opponents by 20 runs is likely better than the team outscoring its opponents by one run.
Using Fangraphs, we use “Pythagorean Record” and “Base Runs” to calculate if a team is outperforming or under-performing its run differential. You can find this data on the Fangraphs Projected Standings page.
Before we delve into the post, here is a look at an explanation for each statistic we will be looking at.
Pythagorean
"You may not know Pythagorean Record by that name, but you’ve likely heard about run differential. Run differential allows you to calculate a team’s Pythagorean Record. The idea here is that how many runs a team scores and allows is a better reflection of their ability and performance than their W/L record."
Base Runs
"Base Runs helps here because it takes into account a team’s performance without considering the sequencing to calculated expected runs scored and runs allowed, and then takes those numbers to generate expected wins and expected losses. There are a lot of ways to get to 4-1 in the standings, but the team’s expected run differential is going to be a better predictor of future success than that 4-1 record going forward."
Let’s take a look at teams that have outperformed their run differentials in the first half of the season. These are the teams we could see regress to their true talent level in the second half, which could potentially lead some of the teams on the list out of a playoff spot, in a highly competitive season.
Next: Number 5