How Did the Mariners Beat Tarik Skubal Three Times — And Can They Do It Again?

Even the best pitchers in baseball lose a game once in a while. Just ask Tarik Skubal. I’m sure you’ve read about it a hundred times by now, but the Mariners have won all three of their games this year where Skubal was the opposing starter. Seattle was the only team to hand him multiple losses during the regular season, and the Tigers dropped Game 2 of the ALDS — technically a no-decision for Skubal — less than a week ago. Now, thanks to his team’s roaring come-from-behind victory in Game 4, Skubal is lined up to start tonight’s decisive Game 5, giving him an opportunity to finally beat the Mariners this year.

I’ll give a warning upfront: This article is going to lean pretty heavily on batter-pitcher matchup stats; we’ll be examining some extremely small samples. But I think it’s an interesting investigation into the strategy that unfolds between familiar foes during a short postseason series.

What I really wanted to know is whether the Mariners had a specific approach that made them so successful against Skubal this year. As I mentioned, Skubal faced the Mariners twice during the regular season. On April 2, in Seattle, he allowed three runs in 5.2 innings; he gave up six hits and three walks while striking out eight. On July 11, he faced them again, this time in Detroit, and allowed four runs in five innings; he gave up just four hits and two walks while striking out five. His Game 2 start this past Sunday was his best yet: He surrendered two runs on five hits and one walk in seven innings while notching nine strikeouts. The two home runs off the bat of Jorge Polanco were his undoing.

Among the batters in the Mariners’ current starting lineup, only Eugenio Suárez and Josh Naylor have failed to earn a hit against Skubal this year; they’ve only faced him during the ALDS, as they weren’t with Seattle earlier in the season and Skubal never faced the Diamondbacks. Polanco had the two home runs on Sunday, and Julio Rodríguez blasted a home run — his only hit off Skubal in 2025 — in the game in July. Shockingly, J.P. Crawford is tied for the team lead with Polanco with three hits off Skubal this season.

If we move past the tiny individual samples and take a look at how the team approached him, does anything jump out at us? Here’s a look at how the Mariners have fared against each of Skubal’s individual pitch types:

Skubal’s two best pitches are his four-seam fastball and his deadly changeup. Seattle’s batters have really struggled against Skubal’s heater, running a woeful .227 wOBA and a minuscule 10% hard-hit rate against it. The team has actually struggled relative to league average against fastballs thrown harder than 97 mph this year; the Mariners produced a .286 wOBA (league average is .295), a -0.75 RV/100 (-0.61), and a 29.6% whiff rate (23.7%) against hard stuff. Skubal’s fastball is a top shelf pitch, better than any other starter’s according to Stuff+, so it’s no surprise they struggled to put it in play with any authority.

The real surprise is how well they’ve fared against Skubal’s changeup and slider. His changeup was arguably the best pitch in all of baseball in 2025 — it led all pitches with a run value of 25 according to Baseball Savant. Despite swinging and missing half the time they offered at his change, the Mariners actually did a bit of damage against the pitch. Rodríguez’s home run in July came off a hanging changeup that was left up in the zone in a 1-2 count:

And then there’s the slider. Skubal’s breaking ball is the worst of his pitches, though it still grades out as an above-average pitch per Stuff+. All the way back in April, Dylan Moore, who is no longer with the Mariners, poked a back door slider over the right field wall for an opposite field home run. More recently, Polanco collected a single off a slider back in July, and his first home run in Game 2 came on a hanging breaking ball:

Was there something about the Mariners approach to Skubal that allowed them to hone in on his secondary offerings? Here are their key plate discipline metrics against him, broken down by pitch type. His pitch type split for all of 2025 for each of these metrics is in parenthesis for context:

The thing that jumps out is the Mariners’ refusal to chase Skubal’s changeup out of the zone. His chase rate on that pitch was nearly 50% in 2025, but the Mariners only chased 34% of the time. He even noted that approach from Polanco after Game 2:

“[Polanco] seemed to have seen the ball pretty well from me. He took some changeups down that were just below [the zone]. Generally when I throw it right there and execute, there’s a good result for me.”

Not only have the Mariners spit on those changeups just out of the zone, they’ve been more aggressive than the rest of the league against the changeups that do fall in the zone. When they’ve managed to force Skubal into the zone, they’ve been able to do some damage. And if Skubal refuses to pitch in the zone, they’re patient enough to take their walks; Seattle led all teams with six walks off Skubal this year.

Knowing how Seattle’s batters have approached him in the past, I’m sure Skubal and battery mate Dillon Dingler are crafting a plan for Game 5. Here’s his pitch mix against them so far:

From April to July, Skubal changed his pitch mix to feature more sinkers and sliders. In his postseason start in Seattle, he switched things up again and cut back on the usage of his changeup, no doubt understanding the patient approach the Mariners have had against his offspeed stuff. The plan for Friday won’t be dramatically different from Skubal’s already established norms, but I’m sure it’ll have its wrinkles. After Game 4, Dingler hinted at how steady the game plan will be:

“We don’t vary too much from what he’s really good at. We don’t venture too far off. We’ll increase offspeed, we’ll increase fastball, we’ll increase slider or changeup, just little tiny things just to get us to that finish line.”

Based on the approach the Mariners have shown in their previous three meetings, perhaps Skubal will lean a little heavier on his four-seam fastball, daring the Mariners to hit his hard stuff. Maybe Seattle’s batters will have worked on hitting high-velocity fastballs during their off day on Thursday. All of this game planning will be tested once the pitches start flying tonight.

The other angle of analysis I wanted to explore was to see if starting pitchers suffered any sort of penalty for starting multiple times within a postseason series. Just like relievers lose their effectiveness the more often they’re used against the same opponent in a short span of time, it follows that starters would suffer a similar negative effect in their second start. As batters get familiar with how a pitcher’s pitches move, they’re better able to pick up on those pitches. It’s the same notion that undergirds the times-through-the-order penalty.

I pulled every pitcher who started multiple times in a single postseason series since 2021, giving me a sample size of 54. Then, I calculated their difference in performance from their first start to their second.

(Update: a calculation error skewed the data in the table above. It has been updated to correct the error.)

On average, across the four metrics I used, pitchers performed worse in their second start; their ERA rose by a quarter of a run, their FIP increased by more than half a run, their wOBA allowed increased by 12 points, and their strikeout-minus-walk rate fell by more than three points. I also calculated the same difference in performance, but removed second starts that were made on short rest to control for potential fatigue effects. Even when limiting the data to pitchers pitching on normal rest, we see that they performed worse in their second start in a postseason series, though the effect was a little less dramatic; their ERA stayed steady, their FIP was up 0.58, their wOBA allowed went up nine points, and their K-BB% dipped 3.1%. Not only will Skubal be making his fourth start against the Mariners this year, this data shows he’ll likely suffer a penalty for having facing them so recently.

We only have to look back to last year to see how Skubal fared in a decisive Game 5 after making a start earlier in the series. Skubal was phenomenal in his Game 1 start against the Guardians in the 2024 ALDS. He threw seven shutout innings, allowing just three hits and striking out eight. Cleveland got the better of him in Game 5, however, scoring five runs — four off a Lane Thomas grand slam in the fifth inning — off Skubal in an eventual 7-3 loss that sent Detroit home for good. Pointing to last year’s Game 5 failure doesn’t necessarily portend a repeat tonight. Skubal has been one of the very best pitchers in baseball for two years now — a quality that surpasses most of the sample from above — so any familiarity penalty could be less pronounced than the data might predict. The Tigers are certainly feeling confident behind their ace.

In the end, Skubal’s success tonight will come down to execution. Will he make the necessary adjustments to keep Seattle’s batters off balance, or will they continue their patient approach against a familiar foe and beat him for the fourth time this year?