What does all of this data mean for the 2019 White Sox? Well, first of all, the prevailing thought was the White Sox would not be a playoff team in 2019. Does their current record change that? How do teams with their end-of-April performance in winning percentage as well as run differential typically end up?
The White Sox ended this April with a 46.2 percent win percentage. Of the 159 teams from 2000-2018 with a winning percentage somewhere between 40-49.9 percent, 28 of those teams made the playoffs. That would give the White Sox a 17.6 percent chance of making the playoffs. While that’s not very good, it is much better than the 0.6 percent chance Fangraphs is currently giving the team.
The run differential data is not exactly encouraging either. The White Sox run differential sits at -13. Teams with a similar run differential, between -10 and -15, made the playoffs six times. The data shows 41 total teams with that kind of run differential.
Purely looking at the data though, there is a little hope for encouragement. At the end of April, the 2003 Marlins had a 45.9 percent win percentage and a -13 run differential. They were a young team coming off a losing season but they went on to win the World Series. Of course, that Marlins team was one of the most surprising teams in baseball history. The likelihood of the Sox turning their current situation into a great season is pretty low.
Now, if someone were to be a pessimist, the 2004 Diamondbacks actually had a better winning percentage and run differential than these 2019 White Sox. They had a 46.8 percent winning percentage and a -9 run differential…and managed to lose 111 games.
As with most things, the Sox are probably in the middle. Improvement seems pretty likely. The 159 teams with an end-of-April winning percentage of 40-49 percent only had five examples ending with 100 or more losses. That’s a 3.1 percent chance of being a 100-loss team based only on win percentage.
Similarly, 153 teams from 2000-2018 have had a run differential of -1 to -20. Two of those ended the year with 100 or more losses. So that result seems quite unlikely for the White Sox this season.