The Milwaukee Brewers stand on the precipice of a championship, holding a commanding 3-games-to-none lead over the Tampa Bay Rays. While several stars have contributed to this postseason run, catcher William Contreras has emerged as the engine of the Brewers’ success, blending elite offensive production with a defensive evolution that has culminated in the mastery of Major League Baseball’s debut Automatic Ball-Strike (ABS) Challenge System.
Contreras, known affectionately as “Wild Bill,” has been a constant presence behind the plate, catching all 11 of the team’s postseason games. Under his guidance, the Milwaukee pitching staff has stifled opponents, posting a collective 2.02 ERA. Offensively, he has been equally formidable, carrying a 1.141 OPS into the final stretch of the World Series with three home runs and eight RBIs. However, it is his strategic use of the head-tap—the signal for an ABS challenge—that has separated him from every other backstop in the league.
During the regular season, Contreras was the most prolific challenger in baseball. He utilized the system 185 times, which was 49 more than the second-most frequent challenger, Tyler Stephenson. Even with such high volume, Contreras remained effective, ranking seventh in the league in Runs Above Average (1.9) with a 57% overturn rate. In the high-stakes environment of October, he has only become more aggressive.
Data indicates that during the regular season, Contreras challenged 38% of incorrectly called pitches when he had a challenge available. In the postseason, that frequency has surged to 63%. His 29 total postseason challenges are more than the totals of the next two closest catchers—the Guardians’ Patrick Bailey and the Rays’ Liam Hicks—combined. This aggression has been rewarded with a 66% success rate in the playoffs, contributing 0.8 Runs Above Average during this tournament alone.
Contreras explained his philosophy by emphasizing confidence over caution. “Whenever I want to challenge, I call it. I’m not afraid to lose my challenge,” he stated. “I trust my pitcher.” He also noted that his challenges often serve a dual purpose beyond merely overturning a single call; he uses the system to map the strike zone for specific hitters, particularly on pitches near the top of the zone.
This multi-faceted contribution was most evident in Game 1 of the World Series. In a 3-2 victory, Contreras recorded two hits, a walk, and an RBI. Defensively, he threw out two would-be base stealers and successfully challenged two ball calls that were overturned into strikes, both of which eventually resulted in strikeouts. Manager Pat Murphy was blunt in his assessment following the win, calling Contreras the player of the game and noting that his contributions were essential to the victory.
Teammates have also voiced their reliance on Contreras’s instincts. Outfielder Garrett Mitchell noted that the team has developed immense trust in the catcher’s judgment, often preferring to save challenges specifically for the high-leverage situations Contreras identifies.
This performance represents a significant leap for a player who was not highly regarded for his defensive prowess when he was first traded to Milwaukee prior to the 2023 season. Now, as the Brewers look to close out the Rays, Contreras has positioned himself as a frontrunner for World Series MVP honors, though teammates Jackson Chourio and Aaron Ashby remain in the conversation. Regardless of the individual accolades, Contreras’s ability to leverage new technology while maintaining traditional elite production has made him the focal point of Milwaukee’s title ambitions.
