How Mariners fared in first year of ABS System

The 2026 season featured the introduction of MLB’s Automated-Ball Strike (ABS) System, and the Seattle Mariners have some work to do to, especially when challenging pitches while at the plate.

Mariners claim switch-hitting local product off waivers

The MLB average during the regular season was for 54% of challenges to be overturned, according to Baseball Savant. The Mariners were among the teams on the short side of that number at 50.7%.

Much of Seattle’s troubles using the ABS system stemmed from its misses while at the plate. The average MLB hitter won 49% of challenges, but Mariners batters were second worst in the league with a 41.7% success rate (68 of 163). That helped Seattle also finish second worst in challenge overturns vs. expected (minus-23.5), which measures net ABS overturns compared to what is expected for a team seeing identical pitches.

Despite being one of MLB’s worst at challenging while on offense, the M’s were tied for the seventh-most walked gained (12) and 10th-most strikeouts erased (23) on challenges.

As for when they were in the field, the M’s were just above the 58% league average with a 59.3% success rate that ranked 13th in MLB. Their 37 strikeouts gained were seventh and 10 walks erased were tied for the 10th least. With 2.9 more overturns than expected, they ranked 13th.

How individual Mariners fared

The struggles the Mariners had with the ABS on offense can largely be attributed to two players: Josh Naylor and Randy Arozarena. Naylor’s 27% success rate (7 of 26) was third worst in MLB among players with at least 25 challenges, and Arozarena was 15th worst at 39% (11 of 28). Naylor and Arozarena combined for nearly one-third (54 of 163) of the Mariners’ challenges on offense.

Cal Raleigh led the club with 14 successful challenges on offense and was its most efficient challenger (minimum five challenges) with a 64% success rate (14 of 22). Raleigh also had the most strikeouts erased (seven) and walks gained (five) on challenges among Mariners, which were tied for second and tied for first, respectively, leaguewide. Additionally, Raleigh’s 4.6 runs gained on offensive challenges were second in baseball, trailing on Houston’s Jose Altuve.

In the field, it was former catcher Mitch Garver who stood out most before he was released in August. Garver had a 74% success rate (25 of 34) on challenges while behind the plate. That was third best among MLB catchers who challenged at least 20 pitches. Raleigh had a 61% success rate (54 of 88) on challenges while catching, and Jhonny Pereda had a 45% success rate (19 of 42).

George Kirby was the only M’s pitcher to challenge for than one pitch, going 1 of 5. His four unsuccessful challenges were tied for the second most among pitchers leaguewide. The three M’s pitchers that challenged one pitch each went 1 for 1.

Does ABS success mean team success?

The first year of the ABS System didn’t show any correlation between successful challenging and team records.

Of the top 10 teams in successful challenges on offense, just three reached the postseason. Of the bottom 10 teams, five made the playoffs, including the 98-win Rays and 103-win Brewers.

Of top 10 teams in successful challenges on defense, four made playoffs. Of the bottom 10 teams, four made the playoffs.

Of the top five teams in most total successful overturns, only the Chicago White Sox, who were fifth, made the playoffs. Meanwhile, two of the bottom five teams reached the postseason. The juggernaut Dodgers, who won 100 games, also had the sixth-least total overturns for.

Seattle Mariners news and more

• These four Seattle Mariners are set to become free agents
• Why Hyphen says Mariners need to ink Logan Gilbert to extension
• M’s player from Luis Castillo trade haul elects free agency

Related

Mariners Notebook: Randy Arozarena named Hank Aaron Award finalistMariners’ Cal Raleigh, Josh Naylor undergo offseason surgeryEx-Mariner José Caballero leads MLB batters in pitch clock violationsFormer Mariners 1B Ty France at center of bizarre play in NLDSPuyallup native Rasmussen takes no-hitter into 8th in ALDS openerRobot umpires flip 54% of challenged calls in ABS debut