The Mariners are rolling.

They’ve scored 55 runs in their current seven-game winning streak. Julio Rodríguez has been impossible to get out and that’s rubbed off on his teammates.

So of course, we want to talk about their defense.

The Mariners rank 9th in MLB in Defensive Runs Saved. So it’s not just the hitting that explains why they’re 15 games over .500.

The key to their ranking is the performance of their outfield. The Mariners outfield ranks 4th in Defensive Runs Saved. The team has a 61.8% out rate on balls hit to the outfield, 2nd-highest in MLB.

Here are the top defensive outfields in MLB.

Team Runs Saved
Blue Jays 45
Padres  25
Guardians 23
Mariners 22

By our measures, Seattle doesn’t necessarily have anyone who’s going to blow you away save for small-sample size superstar Cade Marlowe, whose strong Statcast “burst” numbers have allowed him to make up for slow reactions to the ball off the bat. 

Marlowe made the catch in the tweet above filling in for Rodríguez in center field last night. He’s spent most of his time since his recall in left field, where he has 7 Runs Saved, including a couple of assists, like this one on which he played spoiler for another player’s memorable moment. 

The Mariners have done well with whoever they’ve put in left field. Jarred Kelenic and A.J. Pollock have also combined for 5 Runs Saved there.

But more than anything, the Mariners outfield is good because the team doesn’t play anyone who is bad. All but 73 innings this season have been played by an outfielder who totaled a non-negative number of Runs Saved.

Go figure that Teoscar Hernández has been an unexpected positive contributor in right field. He’s never finished a season with a positive Runs Saved total there but has 4 Runs Saved. 

The Mariners play him deep – at an average depth of 297 feet at T Mobile Park, an average of about 7 feet deeper than they played their right fielder last season.

Hernández had a strong first month, with 5 Runs Saved at the end of April. He’s leveled off since then but his season numbers are still alright. 

Depending on your metric of choice, Rodríguez is either having a great defensive season (Baseball Savant’s Runs Prevented) or one that’s a little above-average (Defensive Runs Saved). The metrics agree that he’s good but differ on the degree, which happens sometimes. In this case, there’s an explanation. Our Defensive Runs Saved separates out the value a team accrues from properly positioning him. Rodriguez, Steven Kwan, and George Springer have each netted 6 Positioning Runs Saved for their teams, the most for any outfielder in MLB this season.

Rodríguez is another player who can make up ground with a burst once the ball has been in the air for 1.5 seconds and that’s led to a bunch of dazzling catches. 


The other player who has given this team a defensive boost is a surprising one. The Mariners were projected to open the season with a pair of Gold Glovers in second baseman Kolten Wong and shortstop J.P. Crawford. But the team’s best defensive infielder by Runs Saved has actually been utility man José Caballero. The soon-to-turn 27-year-old rookie has 9 Runs Saved split primarily between the two middle infield positions.

The Mariners aren’t a perfect defensive team. The numbers from their corner infielders, particularly Ty France and Eugenio Suarez aren’t great (though they’ve put up good numbers at first and third in the past), their primary catcher Cal Raleigh hasn’t quite replicated what he did last season when he ranked 3rd among catchers in Runs Saved, and J.P Crawford hasn’t matched where he was in 2020 and 2021.

But right now there’s enough there both at the plate, on the mound, and in the field to make up for that.