Tuesday, September 30, 2014


If people would cease to care about Derek Jeter in the way that they've ceased caring about interleague play, we would really be on to something.

The 2014 battle between the AL and NL wound down with less suspense than the slow-motion "backing into the playoffs" in the final week of the season, as the AL went 14-4 in its home games during interleague play in September en route to a 15-9 final month to wind up with a 163-137 advantage over the course of the year.

We have several more tables for you in addition to the calendar overview.

First, we've got the overall interleague standings. Part of what got the Royals into the postseason was their superb performance against the NL in 2014 (15-5).

We haven't gone back to look at whether this is something that shows up in the data in other years, but the playoff-bound teams did quite well in interleague play in 2014: 127-93 (.577 WPCT).

Teams that played over .500 but didn't make the postseason (and by the way, did you know that there was only one non-playoff team in the NL this year that managed to finish over .500 this season, as opposed to four in the AL?) also fared rather well in inteleague play: 56-44 (.560 WPCT).

The "bad" (sub-.500) teams took it on the chin: 113-163 (.409 WPCT).

The most interesting chart, however, has nothing to do with individual successes or failures amongst the 30 individual teams with respect to interleague play. It is the ongoing (presumably random) bias that continues to favor the AL in terms of quality of opponent.

As you can see, the AL played only 40% of its games against NL teams with winning records in 2014. That certainly doesn't hurt their prospects any! As the chart shows, the NL--which plays the good teams of the AL reasonably well at home (46-44)--just takes it on the chin in road games against .500+ AL opponents (25-65, .278 WPCT).

We figure that this amounts to about a six-game advantage for the AL over the course of interleague play. Based on calculations that adjust for the "good team" bias, the NL would add six more wins against the AL if games are balanced for quality of opponent. They'd still trail in games won, 157-143, but there's no question that the vagaries of the interleague schedule are not favoring the NL.

And they haven't done so for the past five years: AL teams have played sub-.500 NL opponents in 57% of all interleague games since the 2010 season.