Mariners vs. Blue Jays ALCS Game 6 could be decided by a shared unhittable pitch

Given what's at stake, you have to assume that neither starting pitcher will have a long leash for Game 6 of the American League Championship Series. It could end up being a repeat of Game 2, in which neither Logan Gilbert nor Trey Yesavage made it past the fourth inning.

And yet, both managers will have an excuse to keep rolling with their starter as long as the results are there. For the Seattle Mariners, it'll come down to trusting Gilbert if he's looking like the same guy who led the majors in innings and WHIP just last year. For the Toronto Blue Jays, the more Yesavage gives them means the less they'll need to ask from a bullpen that has a 6.88 ERA in the series.

Even more so than his short-rest start in Game 2, this one has the feeling of a signature moment in the making for Gilbert. With the Mariners just one win shy of reaching the World Series for the first time in their history, it would be all too appropriate if the guy who got them there was the same guy who was the first cornerstone they laid down for their modern era back in 2021.

Why Game 6 of the ALCS will be the Battle of the Splitters

What really matters, though, is whether either or both starters can dominate with a signature pitch they both share: the splitter.

Gilbert's splitter has a case as the most unhittable pitch in baseball, at least among starters. The numbers are there in spades, as this year it had a 50.0 Whiff% and held hitters to a .119 batting average, with only a .099 expected average that led all pitches that ended at least 100 plate appearances.

Though Yesavage's splitter is less established in the pantheon of great pitches, the small-sample-size returns on it are strong enough to make even Gilbert's alter ego, "Walter," blush. Between the regular season and the postseason, Yesavage's splitter boasts a .125 average, a .134 xBA and a ridiculous 57.9 Whiff%.

Yet here's the thing about the first time these two matched up in Game 2 on Monday: neither really had the splitter working.

Yesavage got burned by his splitter on just his 16th pitch of the game, hanging one to Julio Rodríguez that ended up 370 feet away for a three-run homer. Command issues otherwise forced him to largely put his splitter on the shelf. Out of 70 total pitches, he threw only 16 splitters and got only two whiffs.

Gilbert had his own issues with command in Game 2, specifically with his splitter. It was clear from the jump that he didn't have a good feel for it. A good splitter looks like a strike until it falls off the table, and most of the ones he threw were either totally noncompetitive or guilty of catching too much or too little of the strike zone. He threw only 11 splitters out of 58 pitches, with only two whiffs.

It's not really anything new for Gilbert to have days like that with his splitter. He even largely got away from it amid a rough patch in July and August, only to bust the pitch back out again to help fuel a 2.30 ERA in September. It was a major weapon for him again in two appearances in the ALDS, as he used it 28.6 percent of the time and benefited with a 57.1 Whiff% and .125 average.

If there's an ideal scenario for the Mariners in Game 6, it's one in which Yesavage doesn't improve from Game 2 while Gilbert very much does. That could be all she wrote for the Blue Jays, as even Gilbert's quick hook after three innings didn't stop the Mariners from running away with a 10-3 win.

Of course, the Mariners will take a win in Game 6 no matter how they can get it. But if it ends up being Gilbert of all people who clinches the pennant for them, they'll gladly take the heartwarming feeling that will come with it.