NEW YORK — Major League Baseball is having its most-viewed postseason in the United States in 15 years.

Viewership is averaging 4.33 million through the division series, according to MLB and Nielsen, a 30% increase over last year and the best since 2010.

Last Friday’s 15-inning thriller between the Seattle Mariners and Detroit Tigers averaged 8.72 million viewers on Fox, Fox Deportes and streaming. The Mariners’ 3-2 victory in the fifth and deciding game of the AL Division Series was the most-watched division round game on Fox since Detroit’s Game 5 win over the New York Yankees in 2011 averaged 9.72 million.

The two AL Division Series on Fox, FS1 and FS2 averaged 4.15 million, the most-watched division round on any network since the NL Division Series on TBS (Cubs-Cardinals and Mets-Dodgers).

The series between Toronto and the Yankees, which the Blue Jays won in four games, averaged 7.65 million in the U.S. and Canada.

Viewership for all four division series in the U.S. averaged 4.17 million, its highest since 2011, and a 17% jump from last year.

Blue Jays division series games in Canada averaged 3.65 million, a 10% increase from the team’s last ALDS appearance in 2016.

Sunday’s first game of the AL Championship Series between Seattle and Toronto averaged 5.31 million on Fox, Fox Deportes and streaming. That is a 32% increase over last year’s Game 1 of the ALCS between Cleveland and the Yankees on TBS.

Copyright © 2025 ESPN Internet Ventures. All rights reserved.