Blame it on short series, politics and the New York Yankees.

That was the triple-play explanation Turner Sports gave Tuesday for the 20 percent drop in ratings for the first round of Major League Baseball playoffs.

The first 13 Division Series games averaged 4.3 million viewers, compared with 5.4 million in 12 games last year, according to Nielsen Media Research data supplied by Atlanta-based Turner Sports.

The Los Angeles Dodgers-Chicago Cubs game ended in a three-game sweep and was up against the highly watched vice presidential debate Thursday. The other series ended in four games.

And, with the Yankees and Mets not making the playoffs, postseason baseball for the first time in years lacks the bigger draw of a New York team.

This is the second year of TBS’ baseball deal, which gives it TV rights to the entire first round of the playoffs and one of the two league championships. It will broadcast the American League championship starting Friday.

“I think everyone in the industry understands the long-term benefits of the baseball postseason, and we don’t look that closely at ratings. Baseball is still a terrific product, and it sells well,” said Neal Pilson, former president of CBS Sports who now runs his own media consultant firm in Chappaqua, N.Y. “Their production has been good, their talent has been interesting, and their games have been competitive.”