Major League Baseball’s 2025 playoffs continue Saturday with four Division Series matchups, determining which teams will advance to play for the pennant and ultimately compete in the World Series.

Highlighting key X-factors in each series provides an insight into factors that might sway the match results. Here are the analyses:

Los Angeles Dodgers vs. Philadelphia Phillies

• X-factor: Dodgers bullpen

The performance of the Dodgers’ bullpen will be critical, particularly since they have relied heavily on relievers throughout the season. Historically, their bullpen has shown tendencies to blow games, which could be pivotal in this series.

Detroit Tigers vs. Seattle Mariners

• X-factor: The running game

The Mariners are known for their effective stealing and speed on the bases, a strength they aim to exploit against a Tigers team noted for allowing limited steals. This matchup presents a battle of speed versus defensive acumen.

New York Yankees vs. Toronto Blue Jays

• X-factor: Zone adjustments

Batters will need to adapt their approaches to the strike zone throughout this competitive series. Accurately adjusting to umpire calls could mean the difference in close games.

Chicago Cubs vs. Milwaukee Brewers

• X-factor: Milwaukee’s ground balls

The Brewers boast a high ground-ball percentage with notable players like Christian Yelich. Chicago’s defense against grounders could be tested in this matchup, affecting the outcome as both teams have a rich history in their encounters during the regular season.