Does the White Sox April Performance Change Anything?
When there is this much data collected, it would be a waste to not use it for some random facts and some comparisons of other teams’ current performances. First, 15 teams have ended April with a run differential larger than 50. All 15 of those teams won at least 60 percent of their games and three of those teams went on to miss the playoffs. All of them managed to be at least .500 at the end of the year.
The 2011 Indians have the highest April run differential in a season where they ended under .500. At the end of April, they were 18-8 with a positive 46 run differential. After April they went 62-74 with a -102 run differential. That’s a great collapse.
Trying to calculate “luck” in baseball can be very difficult. The stats Baseball Reference uses are pretty good though, looking at 570 total seasons from 2000-2018. Twelve of those seasons had a team winning or losing 10 more games than their run differential would expect. That means 97.9 percent of teams were within 10 games of their expected wins and losses. It isn’t perfect by any stretch, but that is pretty accurate overall.
Run differential and winning percentage both seem quite concerning for this year’s defending World Series champion Red Sox. Thirty-three teams have had a run differential of -25 through -30 in this data set and just three of those teams have made the playoffs. The Red Sox’s 43.3 percent winning percentage compares much more closely to a bottom-ten team than a defending World Series champ. They have improved lately, but they may be that team that lost a division in the first month of the season.
A team like the Reds should have a lot more hope than their winning percentage would imply. I’m sure they would trade their positive run differential for an over .500 winning percentage, but their run differential seems to point to them being a better team than they have shown. Based purely on runs scored and runs allowed, they are the least-lucky team in baseball through the month of April.
It is kind of amazing that the New York Yankees have stayed where they are in the standings and have maintained such a good run differential given the injuries they have had to deal with. If their performance improves throughout the course of the season, they will be extremely difficult for the Tampa Bay Rays to deal with.
In the end, April winning percentage is obviously important but April run differential is statistically more important. April performance has very little to do with performance after the month of April. All April performance seems to do is set teams up for potential success and crush hopes of successful seasons pretty early.