The 2025 MLB postseason has reached its penultimate stage, with the American League Championship Series (ALCS) and National League Championship Series (NLCS) poised to determine the World Series contenders. After thrilling Division Series that saw dramatic extra-inning heroics and dominant pitching performances, the final four teams—Toronto Blue Jays, Seattle Mariners, Los Angeles Dodgers, and Milwaukee Brewers—are ready to clash. The ALCS kicks off Sunday in Toronto, while the NLCS begins Monday in Milwaukee. Here’s a breakdown of each series, including brief intros highlighting key dynamics. ALCS: Toronto Blue Jays vs. Seattle Mariners The Blue Jays, who clinched the AL East for the first time since 2015 and earned a first-round bye, enter as the top seed with home-field advantage through the series. They’ll face a resilient Mariners squad that grinded out a 15-inning thriller in ALDS Game 5 to eliminate the Detroit Tigers—their first ALCS appearance since 2001. Toronto won the regular-season series 4-2, but early-season matchups may not predict October intensity. Expect a pitcher’s duel, with Toronto’s deep lineup testing Seattle’s breakout splitter-heavy rotation, including emerging ace Trey Yesavage. NLCS: Los Angeles Dodgers vs. Milwaukee Brewers Fresh off a bye as the NL’s top seed, the powerhouse Dodgers—bolstered by star power and a deep bullpen—look to leverage their high-velocity hitting against the upstart Brewers. Milwaukee, the NL Central champs, clawed past division rival Chicago Cubs in a decisive 3-1 Game 5 victory, fueled by rookie Jacob Misiorowski’s electric arm and opportunistic offense (solo homers from William Contreras, Andrew Vaughn, and Brice Turang). The Brewers ranked third in MLB runs during the regular season but thrive on walks, steals, and small-ball—tactics that could exploit LA’s occasional power outages. This matchup pits Dodgers’ firepower against Milwaukee’s gritty, balanced attack. Tune in to FOX/FS1 for ALCS action and TBS for the NLCS. The winners advance to the World Series, October 24-November 1 on FOX. Who will claim the pennant?