The Seattle Mariners have the best pitching in MLB in 2023, yet still, they are 21-22 and on the outside looking in on the playoff picture. That is due to the lineup being asleep at the wheel to start the year.
Entering the new year, MLB ranked the team T-10th in terms of rotation. However, that ranking lacked inclusion of breakout Bryce Miller and obviously did not account for any injuries of any pitchers. As for the bullpen, the Mariners came in ranked 5th despite lacking a shutdown lefty.
Clearly, the Mariners were expected to have a good, if not near-elite pitching staff, but certainly were not expected to have the best staff in the league. But through 43 games, the team has put up a league-leading 8.5 Fangraphs WAR, a full 1.3 WAR above second place.
Through 387.2 staff innings, they are 12th with 8.85 strikeouts per nine innings, league-leading 2.67 walks per nine, league-leading 0.70 home runs per nine, league-leading FIP with 3.33 and second in expected FIP with 3.86.
They have done all of that production with the 18th-highest pitching payroll, clearly being able to utilize lower paychecks to get high production. On an individual level, the team has four players above 1.0 WAR, the only team in the league to accomplish the feat thus far.
Luis Castillo has 1.6 WAR ($17.0 million), George Kirby has 1.5 WAR ($758,300), Logan Gilbert has 1.3 WAR ($767,300) and Bryce Miller has 1.0 WAR ($592,263).
Along with their cheap contracts, their staff is relatively young. With an average age of 28.5, they are nearly a year younger than the league average for 2023. The team will have a similar staff for several years to come, with their best pitchers under contract for the next half-decade.
Despite the dominance of the staff, giving up just 172 runs, their Pythagorean win-loss expectancy, a formula that determines what a team’s record should be based on their runs scored and runs allowed, is just 24-19, nearly entirely because of the lack of consistent offensive production.
The production from their pitching staff has continued to dominate despite some hiccups. A notable one has been the bad luck of Matt Brash, a pitcher who boasts an ERA above 5.00 despite elite strikeout rates.
With how good the Mariners pitching staff has been, it is only a matter of time for the team as a whole to find their groove on go on a winning streak, potentially one similar to the 14-game streak from 2022 that brought them clearly into playoff contention.