The Seattle Mariners are outscoring their opponents. And in the American League in 2026, that is most rare.
At the time of writing, only five teams in the AL have a positive run differential. The New York Yankees are streets ahead of the competition with a +101 mark, followed by the Tampa Bay Rays (+24) and the upstart Chicago White Sox (+18). The only other two positive differentials are the +5 belonging to the somehow-10-games-under-.500 Boston Red Sox – and the other, a +4, to these Mariners.
The positive spin, then, would be to say that the Mariners have quietly built one of the league’s strongest run differentials while leading the AL West despite spending long stretches looking anything but dominant. Realistically, the Mariners have disappointed relative to expectation. But perhaps there is some comfort in knowing that they should be better than this – and that only one thing has to change before they will be.
Mixed Mariners First Half
To be sure, the Mariners have not looked anything like a powerhouse. They have hovered around .500 for much of the year, endured offensive cold spells, dealt with injuries and watched the rest of the division remain stubbornly within reach, even knowing how bad they are. Yet the positive run differential could be interpreted as a sign that the 2026 Mariners will ultimately be better than its halfway win-loss record might suggest.
Run differential is not a perfect predictor, as evidenced by the fact that the Rays lead the Yankees despite the above deficit. But over a full season, it is usually one of the better indicators of team quality. A club can get lucky in close games for a month or two, but teams that consistently score more runs than they allow tend to find themselves in contention. The Mariners have done exactly that, and the biggest reason is in how the pitching has once again carried the season.
For several years, the Mariners have built around run prevention, and that remains the case in 2026. Opposing teams have struggled to put together big innings against Seattle, and even when the offense disappears for stretches, the pitching staff (sixth in the majors in team ERA, and third in the AL) generally keeps games within reach. The choice to go to a six-man rotation is paying dividends, and although fifth starter Luis Castillo and closer Andros Munoz are not yet operating at full power, they are being picked up by Bryan Woo, Bryce Miller, Emerson Hancock, Logan Gilbert, George Kirby and Eduard Bazardo. If the Mariners score more than two runs, they can usually win.
“If.”
The Obvious Thing Missing
The offense has been the problem. The Mariners ranked second-last in the AL and fifth-last in the entirety of baseball with a .695 OPS, and although the ball is still leaving the yard, the offense as a whole is distinctly below par. And the reason for that is obvious – Cal Raleigh is a shadow of his former self.
After hitting 60 home runs last season, setting the record for a catcher, and coming a close second in the MVP award, Raleigh has gotten nothing of the sort going this year. In 200 at-bats, he is hitting only .165 with eight home runs, good for only a .578 OPS, going from MVP territory to hitting about the same as Victor Robles. Injury has not helped, but Raleigh is a different man at the plate, with the nightly long bombs turning into nightly pop-outs. The rest of the line-up has performed largely as expected, but without their biggest bat playing at even anything near league-average level, it is not enough,
Still, the broader picture remains encouraging. The Mariners entered this week in first place in the AL West and recently welcomed Randy Arozarena back from the injured list, giving the line-up another established contributor for the second-half push. The record is good enough and the position in the standings is too. But perhaps most importantly, the run differential suggests there may be more substance behind Seattle’s season than many realised. Even with Raleigh being not just a non-factor, but a negative factor so far, the Mariners are coming out slightly ahead.
At some point, you would expect, Raleigh’s bat will come back. And if this is the baseline without him, then they are going to be fine.
The Mariners are Much Better Than This