What’s behind Mariners’ drastic home success, road struggles?

Jun 17, 2024, 3:06 PM | Updated: Jun 18, 2024, 7:58 am

Logan Gilbert of the Seattle Mariners walks to the dugout before a game at T-Mobile Park. (Steph Chambers/Getty Images)

(Steph Chambers/Getty Images)

Seattle Sports

If it seems like the Seattle Mariners have been particularly dominant at T-Mobile Park this season, your eyes aren’t deceiving you.

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The first-place Mariners are a dazzling 27-12 in their home ballpark, which is the third-best home record in the majors. They have won a whopping nine consecutive series at home, highlighted by their massive sweep of the defending World Series champion Texas Rangers this past weekend.

As one of the most pitcher-friendly ballparks in the league, T-Mobile Park is a perfect match for Seattle’s elite starting rotation. And the Mariners have taken full advantage of that, routinely shutting down opponents and grinding out a slew of low-scoring wins. According to FanGraphs, they lead the majors in home ERA (2.54), home opponents’ batting average (.195), home opponents’ slugging percentage (.311) and home strikeout rate (27%).

However, it’s been a drastically different story on the road. Seattle is just 16-19 away from home, where its pitching staff hasn’t had nearly the same success. The Mariners rank 19th in road ERA (4.47), 14th in road opponents’ batting average (.238), 21st in road opponents’ slugging percentage (.410) and 25th in road strikeout rate (20.1%).

During his appearance on Seattle Sports’ Brock and Salk on Monday, ESPN MLB senior writer David Schoenfield brought up the night-and-day contrast between the Mariners’ home and road splits.

“I’m gonna throw you guys for a little bit of a twist here: Is it possible that actually Seattle’s pitching is a little overrated and the offense a little underrated?” Schoenfield said. “Because look at these numbers: 2.54 ERA at home. They’re unbeatable at home. The pitching just dominates there. But on the road, 4.47 ERA. That’s only 19th in the majors.”

As Schoenfield mentioned, the differing home and road splits don’t just pertain to the Mariners’ pitching. Their offense also has a noticeable contrast, though not nearly as dramatic. At home, they rank 29th in batting average (.213), 27th in on-base percentage (.298), 26th in slugging percentage (.358) and 28th in OPS (.656). They are better on the road, where they rank 25th in batting average (.228), 20th in on-base percentage (.303), 17th in slugging percentage (.376) and 16th in OPS (.679).

“Their offense (is) actually middle of the pack on the road,” Schoenfield said. “Now, I’m not defending the offense. They still strike out too much. They’re gonna have to look to make a couple upgrades. I know everyone’s down on the hitting, but for whatever reason, nobody can hit at T-Mobile this year. Every game there feels like it’s 2-0 or something like that. So you’ve gotta factor that in.”

Why the big difference?

The most likely explanation for the substantial contrast, of course, is the pitcher-friendly nature of T-Mobile Park. Ever since the stadium opened in 1999, it has been considered one of the most difficult places to hit, due to its deep dimensions, the cold Pacific Northwest climate and a challenging batter’s eye backdrop in center field.

The numbers certainly back up T-Mobile Park’s pitcher-friendly reputation. The most common way to measure a ballpark’s impact on the game, independent of team quality, is through Statcast’s park factor. Park factor is scaled so that a neutral ballpark is 100. For each number above 100, the ballpark favors hitters by 1% more than the league average. For each number below 100, the park benefits pitchers by 1% more than the league average.

T-Mobile Park has a three-year rolling-average park factor of 92, which is the lowest in the majors. The next-lowest park factor belongs to the New York Mets’ Citi Field at 95. The highest park factor is the Colorado Rockies’ Coors Field at 112.

As Michael Bumpus mentioned Monday on Seattle Sports’ Bump and Stacy, the Mariners and their talented pitching staff have clearly figured out how to maximize T-Mobile Park to their advantage.

“This is a pitcher’s ballpark,” Bumpus said. “The same things that we were concerned about when it comes to our bats at home is the same thing that gives our pitchers the advantage. Plus, they’re nasty on the mound. So you combine the nastiness that they have as far as the execution, velocity and all that good stuff with the park itself, it’s supposed to look like this.

“These pitchers are taking complete advantage of (T-Mobile Park),” he added. “The best rotation and one of the hardest parks to hit – with those powers combined, this is what you get.”

Listen to the full conversation with ESPN’s David Schoenfield on Brock and Salk at this link or in the audio player near the top of this story. Listen to the full discussion on Bump and Stacy at this link or in the audio player near the bottom of this story.