It’s August 26, and the Seattle Mariners are 69-58. After sweeping a two-game series from the A’s, they’re just one game back of second place in the American League West, and they’re firmly in the Wild Card scrum. This wasn’t supposed to happen. The Mariners were supposed to be battling the Rangers for fourth place not trying to end a 19-year playoff drought.
This also shouldn’t be happening. In reality, the Mariners aren’t much better than what the projections said they would be. They don’t have a bunch of players hitting their 90th percentile projections like the Giants, nor have they benefitted from a division-wide collapse like the White Sox.
By fWAR, Seattle’s offense ranks 26th in the majors, and the starting rotation ranks 24th. The bullpen ranks third in MLB thanks to Paul Sewald and Drew Steckenrider. Opponents have outscored Seattle by 56 runs. Their Pythagorean record has them 11 games under .500, not over. The Mariners have been bad in a competitive division, yet here they are, photo-bombing the playoff picture.
Manager Scott Servais dismissed the poor run differential because according to him, the team has a +90 Fun Differential. Servais’s pun is good, but it’s not much different than when someone says, “Oh yeah? Well, they lead the league is xGRIT.”
Servais mentioned they had a -9 run differential on the road trip and a plus 90 fun differential— Ryan Divish (@RyanDivish) August 24, 2021
Also @StoneLarry has a pun differential https://t.co/jheKrt4IAF
Servais isn’t completely wrong to poopoo run differential. The metric can be misleading in small samples. On that road trip he referenced, the Mariners won six of eight games, but the two games they lost were absolute blowouts. Seattle lost two games to Houston 12-3 and then 16-1.
That’s part of a season-long trend: they don’t just lose, they get whomped. Per Baseball Reference, Seattle is 8-24 in blowout games (games decided by five runs or more.) Not surprisingly, the Mariners fare much better in one-run games as they’ve maintained a 26-14 record in those contests. In all other games (games decided by 2-4 runs), the Mariners are 35-20. If the Mariners can keep it close, they have a decent shot of coming out on top.
That’s not the typical recipe for success—good teams don’t make a habit of getting blown out—but it has worked. Teams can finish strong despite getting outscored. Andrew Simon wrote that in 162-game seasons five teams have managed to qualify for the postseason despite negative run differentials. No team has accomplished that feat with a Pythag as poor as the Mariners’ though.
Indeed, FanGraphs only gives the Mariners a 4.5 percent chance of reaching the playoffs. Baseball Prospectus is a little more optimistic giving them an 8.4 percent chance of making it to the postseason. Even if the Mariners were supposed to be here, leapfrogging a team is difficult. Seattle has seven more games against the A’s and six against the Astros, so those will be critical games to the Mariners’ postseason dreams. Of course, so will the other 22 games, but Seattle has an easy, breezy schedule outside of three games against the Red Sox.
Seattle is going to need Oakland’s tailspin to continue and for Houston to stumble. Even then, the postseason is still a distant possibility. But the same could be said for the Mariners’ having a winning record three-quarters of the way through the season.
Kenny Kelly is the managing editor of Beyond the Box Score.