Junior Circuit Once Again Tipping the Interleague Scales

(The following is being syndicated from The Captain’s Blog; follow me on Twitter at@williamnyy23).

Last season, the National League won the All Star Game, World Series, and 48% of regular season games against the American League.  After years of being dominated by the junior circuit, it appeared as if the N.L. was starting to narrow the gap. With one more week in interleague remaining on the schedule, however, the reports of the National League’s resurgence may have been exaggerated.

Interleague Winning Percentage, by League

Source: Baseball-reference.com

Until the Padres and Dodgers rallied late to win their games on Sunday, it looked as if the American League was in line to match the highest win total for any day of interleague play (13 wins by the N.L. on June 15, 2002). Even so, the A.L.’s 11 victories in 14 games tied for the third highest win total and fifth highest winning percentage by either league on any single day with at least 10 interleague games. In addition, the banner day increased the American League’s overall interleague record to 96-72, which would rank as the third highest winning percentage since the two leagues started squaring off in the regular season.

Highest League Winning Percentage in an Interleague Day

Note: Based on a minimum of 10 interleague games played.
Source: Baseball-reference.com

The kneejerk reaction is to attribute the A.L.’s advantage in interleague play to the DH, but a more a careful analysis suggests that probably isn’t the reason. Besides, this year, the A.L. actually has a much better record when playing in an N.L ballpark. Whether it’s the migration of high profile free agents from the NL to AL, impetus created by needing to keep up with perennial contenders like the Yankees and Red Sox, extension of cyclical phenomenon, or some combination of all three, the playing field between the two leagues hasn’t quite evened out just yet.

A.L. Interleague Record, Home and Road Split

Source: Baseball-reference.com

The Yankees have been a big part of the A.L.’s success against the National League. At 10-2, the Bronx Bombers currently have the best record in interleague play. The same is also true all-time. Since 1997, the Yankees have won almost 62% of all contests against the other league, more than any other franchise. If the Yankees, who have won nine consecutive interleague games, can continue to run the string, they would not only tie for the most victories in one season, but also set the record for the longest winning streak against the opposing league (eight of the top-10 streaks were compiled by American League teams).

Longest Winning Streaks in Interleague Play
  Source: Baseball-reference.com

Although a lot of interleague statistics can be trivial, the American League’s continued dominance over the National League seems well established. Fans of the senior circuit shouldn’t fret too much, however. With the Houston Astros, who have not had a winning interleague season since 2004, crossing over to the American League in 2013, some relief is in sight.

Follow Me On Twitter