A new bench mark

The Mariners are pinch hitting at record pace

The Mariners are bad at pinch hitting, and they do it more than anyone.

The Mariners have called on pinch hitters 118 times this year, the most in MLB. If they keep it up, they’ll set the record for most pinch-hit plate appearances by an American League team since Fangraphs began tracking in 2002. Their 62 wRC+ in those spots suggests the strategy hasn’t really worked.

The logic of the pinch hitter is that the batter coming into the game offers a better matchup than the batter coming out. Teams don’t sub in-and-out players for the sake of giving the manager screen time but because they think it will help them win. The Mariners likely have all sorts of data to inform those decisions: handedness splits, pitcher repertoires, ideal swing paths, and more. It’s tough to argue with that. We don’t have their data, we don’t have the sample size to argue with their tendencies, and we don’t know what would have happened if they hadn’t pinch hit — maybe a 62 wRC+ in those situations is a relative bargain.

But what we can say is the Mariners depend on their bench more than any other team. That’s not ideal. Most batters are better in the starting lineup because they benefit from seeing pitches and pitchers throughout a game — they get comfortable. It’s not easy to hop off the bench in the seventh inning to face a fresh reliever in a big spot, especially for a batter who hasn’t played for two or three days. And because benches are only so deep, those batters can’t always be subbed out later, making them easy targets for opposing managers to “platoon-o-reverse” in their next at-bat. The Mariners have seven batters with at least 10 plate appearances as substitutes in 2025. They have a combined 66 tOPS+, meaning they’ve been about 34% worse off the bench than in the starting lineup.

Miles Mastrobuoni and Mitch Garver have been decent in this off-the-bench role, as was Rowdy Tellez during his time with the club. I wrote last week about Dylan Moore’s struggles after losing his full-time job in June. Several other players have had a small handful of chances, mostly to no avail. Then there’s Donovan Solano, the Mariners’ first choice off the bench against lefties. Solano has 19 plate appearances as a pinch hitter this year. He has one hit (a single), no walks, six strikeouts, and three ground-ball double plays — good for a -77 wRC+. His -4.2 wRAA as a pinch hitter is by far the worst mark in MLB this year, and he’s on pace to be the worst-ever pinch hitter on the Fangraphs leaderboard. His full wRC+ against lefties is down to 22; his wRC+ against righties is up to 161. Why the Mariners insist on using him this way is beyond me.

The Mariners’ poor pinch hitting hasn’t kept them from being a productive lineup overall. Their 112 wRC+ this year is fifth-best in MLB — that’s tough to quibble with. But pinch hitters tend to show up later in games when the stakes are higher, meaning their at-bats carry outsized influence not captured by broader run estimates. Nearly 10% of the Mariners’ high leverage plate appearances this year have gone to pinch hitters, and they generally haven’t come through. Here’s their performance by leverage:

The full consequence of this “platoon and shuffle” strategy is unclear. Again, we don’t know what would have happened with more conventional bench management. The Mariners have several players with large platoon splits, and it’s possible the “status quo” batters would have performed similarly to, or even worse than, the pinch hitters.

But the prevalence of this strategy says something about the Mariners’ roster. Only four batters — Cal Raleigh, Julio Rodríguez, J.P. Crawford and Randy Arozarena — have locked down everyday lineup spots. And to their credit, they’ve (collectively) maintained steady excellence throughout the first three months. The other half of the lineup is where we find the shufflers, whose up-and-down performances have defined the season’s shape. The plot below shows the Mariners’ wOBA rolled over 30 games, split between the four primary starters and everyone else:

This isn’t a wholesale rebuke of platoons, pinch hitters or “flexibility.” I like that the Mariners are trying to find a place for the one-sided production of guys like Dom Canzone and Luke Raley. What they offer is quite valuable when coupled with a symmetrical other. But the scale at which the Mariners have committed to this in-game shuffling tactic seems, well, inefficient and inflexible. They need fewer options. They need more good players.