Mains: One-run games and in-season variance

From SABR member Rob Mains at Baseball Prospectus on July 3, 2019:

The Yankees, as you probably know, are off to a strong start. The Giants are not. The Rays are playing well, in contrast to the Royals. You don’t need me to tell you that.

Those pairs of teams have similarities, however. Through their first 81 games — the halfway point of the 162-game schedule — the Yankees had the best record in one-run games, a .722 winning percentage (13-5). The Giants’ .680 winning percentage (17-8) was second-best. The Royals had won just five of 21 games decided by a run, a .238 winning percentage that was the worst in the majors. The Rays’ .333 (5-10) was tied with the Angels (6-12) for the second-worst.

In March, I wrote a pair of articles about one-run games and blowouts. The conclusion, consistent with other work on the subject, is that a team’s record in one-run games during a given season has little or no correlation to its record in one-run games the following season, nor its overall record the next season. In other words, doing well (or poorly) in one-run games isn’t predictive. It’s lucky.

Read the full article here:

Originally published: July 3, 2019. Last Updated: July 3, 2019.