Blue Jays Prove They Are George Kirby’s Nightmare Matchup in ALCS Game 3

SEATTLE — There’s an age-old question among pitching philosophers. Should an approach focus more on the pitcher’s strengths or the hitter’s weaknesses? In my experience, pitchers do not ask themselves this question, though. They almost always prefer to pitch to their own strengths. They might tweak their strategy if a hitter has an obvious and exploitable weakness that they feel comfortable attacking, but mostly they’d rather stick to what they do best.

But what happens when what a pitcher does best aligns perfectly with what his opponent does best? When it’s not just that he’s ignoring the hitter’s weakness, but that he’s also pitching to the hitter’s strength? Game 3 of the ALCS between the Mariners and the Blue Jays gave us a data point to consider when answering that question. Toronto walked away with a 13-4 victory in Seattle to cut the Mariners’ series lead to 2-1, and did so by sticking to its strengths in the batter’s box.

George Kirby, who took the ball for the Mariners on Wednesday night, likes to attack the zone, where he collects strikeouts like Pokémon cards. In 2025, he ranked 18th among starting pitchers with at least 100 innings pitched in K/9, at 9.79. Kirby also places a heavy emphasis on throwing strike one. He reached an 0-1 count against 54% of the batters he faced during the regular season (league average is 50%), and he gets visibly angry with himself when he issues a walk (if you listen closely after he issues ball four in this clip, you’ll hear some colorful language).

Kirby first established himself as a command and control monster in 2023, when he posted a league-best BB/9 of 0.90 to complement his 8.12 K/9. As noted, he accrued strikeouts at a higher clip this year, but he also issued more walks, with a BB/9 of 2.07. That was still good for 20th best in the majors among starting pitchers in 2025 (again, minimum 100 innings pitched), but more than double his personal best.

Kirby battled shoulder inflammation early in the year, pushing his season debut to May. Since then, he’s been throwing from a lower arm angle, and he struggled to locate his sinker for most of the season. But during a mid-September bullpen session, he made an adjustment and started using the same grip that Bryan Woo uses for the pitch. The change wasn’t dramatic, it was more of an orientation shift. In Kirby’s words, he turned it “a little bit.” The new grip helped him rack up 31 punchouts while allowing just three earned runs over 17 1/3 innings during his final three starts of the season. He carried that performance into October, entering Thursday night’s matchup with a 2.70 ERA, 12.60 K/9, and 0.90 BB/9 in his first two postseason starts.

It’s clear Kirby’s preferred strategy is to dominate the zone, but the Blue Jays are allergic to striking out, posting the league’s lowest strikeout rate during the regular season, at 17.8%, to go with the league’s highest contact rate and fifth-highest swing rate. They’re free swingers, but they don’t often miss. In Game 2, Kirby’s teammate Logan Gilbert, who led all starters in K% this year (minimum 100 innings pitched), managed just two strikeouts against the Jays and was chased from the game after just three innings of work. Granted, that was the version of Gilbert recovering from throwing 34 high-stress pitches over two innings out of the bullpen in extras during Game 5 a couple of days prior. So perhaps Kirby, starting on regular rest, would fare better.

Reader, he did not.

For the first two innings, Kirby mostly stuck to his four-seam fastball and sinker, living largely on the edges of the zone. But in the third, the Jays started to punish his fastball-heavy approach. As a first-pitch sinker from Kirby passed over the chalk line of the right-handed batter’s box, third baseman Ernie Clement pulled his hands in and drove the pitch to left field for a double. Shortstop Andrés Giménez fouled off his first-pitch sinker from Kirby, then sent a four-seamer beyond the right field fence to tie the game, 2-2.

With his fastballs under attack, Kirby went to his slider. It took Kirby an additional 25 pitches to get out of the inning. Fifteen of those 25 pitches were sliders. The approach worked well enough on George Springer, who flied out to right fielder Victor Robles in foul territory for the first out of the inning. Left fielder Nathan Lukes saw two sliders, taking the first for a ball and fouling off the second, before shooting a sinker on the inner black up the middle for a single. Then, first baseman Vladimir Guerrero Jr. got two sliders over the middle of the plate and hit the second one off the left field wall for a double. Next, Kirby ran a full count against right fielder Anthony Santander, a plate appearance that included four non-competitive sliders below the zone. On the sixth pitch of the matchup, Kirby used a four-seamer to get Santander to ground out.

With two outs, Kirby then walked catcher Alejandro Kirk to load the bases on five pitches, missing badly with two sliders in the dirt. After blocking those two sliders, Mariners catcher Cal Raleigh immediately called for another slider as the first pitch to Daulton Varsho. Kirby spiked it and Lukes scored from third on the wild pitch. With runners on second and third, Kirby went back to the slider and got a whiff from Varsho despite missing well below the zone. Kirby’s feel for the slider was completely in the wind, so Raleigh next called for a high fastball, which Varsho hit for a double, driving in the fourth and fifth runs of the inning. Third baseman Addison Barger then grounded out on the first pitch of the plate appearance — a sinker just above the zone — to mercifully end the inning.

Despite maintaining his recently rediscovered feel for his sinker, the pitch works best when playing off an effective slider. The two pitches are designed to mirror one another’s spin axis so that they look the same out of the hand before breaking in opposite directions, with the sinker darting arm side and the slider bending glove side. But nearly all of Kirby’s sliders in Game 3 were either middle-of-the-plate hangers or well outside the zone, fooling no one and making for easy swing decisions. The Toronto offense played to its strength, taking aggressive swings on fastballs in early counts and forcing Kirby to be more slider-forward. Starting hitters with his slider worked well in ALDS Game 5 against the Tigers, but on Wednesday night Kirby’s slider offered no refuge. Instead, the Jays did what they do best: Swing early, swing often, put the ball in play, and let good things happen.

In all, Kirby allowed eight earned runs on eight hits and two walks with four strikeouts over four innings pitched. Eight earned runs in a single outing was a season high for Kirby and matched his career high, set in a game against the Guardians on April 4, 2024. Eight runs allowed also matched a franchise high in postseason play. The only other Mariner to yield eight runs in a playoff game was Paul Abbott in Game 3 of the ALDS on October 3, 2001.

Those eight runs were largely generated by Guerrero Jr., who went 4-for-4 and finished a triple shy of the cycle, and Giménez, who tallied three hits, including his game-tying home run in the third. That type of performance is expected from Guerrero Jr., who signed a 14-year, $500 million contract extension to be the face of the franchise back in April. But Giménez was an unlikely hero after finishing the regular season with a 70 wRC+ and tallying just four hits during the divisional round. Giménez surprised even himself, saying after the game that on his home run swing in the third, his focus was on advancing the runner, “I swung hard, but basically I was trying to hit the ball a little bit in front, just to hit it to that part of the field so Ernie [Clement] could get to third.” And then with a laugh he added, “But, you know, I’m OK with what happened.”

For the Blue Jays on defense, Shane Bieber toed the rubber following a rough outing against the Yankees in Game 3 of the ALDS, when he allowed three runs (two earned) and a bunch of hard contact over 2 2/3 innings. But in this matchup, Bieber held an advantage that Kirby did not. While Kirby’s typical approach played directly into the hands of the Toronto offense, Bieber’s strengths set him up perfectly to exploit Seattle’s weaknesses.

Like the Blue Jays, the Mariners land in the top third of the league by swing rate, but their aggressiveness at the plate doesn’t generate nearly as much contact. While Toronto’s whiff rate sits around four percentage points below average, Seattle’s clocks in two percentage points above average. The Mariners do more damage when they make contact, posting a .380 wOBA on contact, compared to .365 for the Blue Jays and the .364 league average, but the swing-and-miss leaves them vulnerable to strikeouts and, as such, they own the league’s seventh-highest K%, at 23.3%.

As Bieber has built back up following his April 2024 elbow surgery, his performance has been uneven, but when the best version of Bieber is present, it typically involves a bunch of swing-and-miss, en route to a slew of strikeouts and very few walks. He works both north/south and east/west, allowing all of his secondaries to generate whiffs when he’s locating well. At times this year he’s struggled to command his cutter, which eats into the effectiveness of his slider, since both pitches primarily generate vertical movement and play off one another to change the hitter’s eye level. Without an effective cutter, one of his best pitches for getting whiffs suffers. But the cutter was working on Wednesday, which helped Bieber post a 58.3% whiff rate on 12 swings against his slider after averaging a 36.7% whiff rate on the pitch over his seven starts during the regular season. Overall, the swingin’ M’s missed on 37.8% of their offerings against Bieber, which is in line with the whiff rates he posted in seasons where he’s received Cy Young votes.

Seattle’s tendencies at the plate matched up perfectly with how Bieber likes to work hitters, and in Game 3, Bieber had all the necessary tools to execute his ideal game plan. He did struggle to locate his pitches in the first inning. Randy Arozarena led off with a walk, then Julio Rodríguez homered on a fastball he intended to throw down and away but left middle-in. Jorge Polanco followed up with a double on a hanging curveball, but after a shaky first inning, the Mariners managed just two additional hits off Bieber. By the second inning Bieber was locked in. He struck out the side on 12 pitches and cruised through the next four innings, striking out eight in all and allowing that lone walk.

Game 3 of the ALCS was decided by which starting pitcher’s strengths won out over a strong offense with a swing-centric identity. Now that challenge falls to Max Scherzer, making his first start this postseason after the Blue Jays left him off the ALDS roster, and Luis Castillo to attempt to do the same in Game 4 on Thursday.