MacKenzie Gore Kicked Major Butt on Opening Day

Man for man, the quality of starting pitching will never be higher all year than it is on Opening Day. And there were some good performances. Framber Valdez shut out the Mets and their brand-new Juan Soto for seven innings. Zack Wheeler shoved for six innings in a no-decision for the Phillies. Nathan Eovaldi struck out nine with no walks and three hits in six innings of a no-decision for the Rangers. Sean Burke, believe it or not, allowed only three hits in six scoreless frames for the first-place White Sox!

But the best performance on this Day of Aces came from a pitcher most people wouldn’t consider worthy of the title: MacKenzie Gore. The 26-year-old lefty was once the best pitching prospect in the game, but expectations settled down some. Around this time last year, I was happy he’d developed into a reliable mid-rotation starter.

That’s not what he pitched like against Wheeler and the Phillies on Opening Day. In two trips through the order, Gore struck out 13 batters, allowing only a single baserunner, who was erased on a stolen base attempt. Gore set a new Nationals/Expos franchise record for strikeouts on Opening Day, and became just the 10th pitcher in major league history to strike out 13 or more batters in an Opening Day start for any team.

The only Opening Day starter to strike out as many or more batters in six or fewer innings was Shane Bieber, who K’d 14 Royals on Opening Day 2020. Bieber’s performance is also the only other one of the 10 13-plus-strikeout Opening Day starts to come in the 21st Century. So if you knew nothing about Gore’s performance other than his strikeout total, you’d know enough to be impressed.

Gore did have a couple things going in his favor; this Phillies lineup will expand the zone when things aren’t going well. Even facing a lefty, manager Rob Thomson trotted out five left-handed hitters. And the game started at 4:05 p.m. The late-afternoon baseball drinking game has but one rule: Take a shot every time the announcers talk about the shadows. And Gore took full advantage of those.

But Gore also hit 98 mph with his fastball and showed a slider with less velocity but more IVB than what he was throwing last year. Here’s his first-inning strikeout of Bryce Harper from Thursday afternoon.

For comparison, here’s a strikeout of another left-handed hitter, Angels first baseman Nolan Schanuel, in Nationals Park last August.

Both pitches have extreme horizontal sweep, but I promise, Gore was getting different movement on his slider than usual.

Gore threw 23 of those sliders, all to lefties, and they simply could not cope with it. They swung at 10 sliders and missed eight of them. Only Bryson Stott managed to put one in play, and given the result — a 77.7-mph popout — he might as well have swung and missed.

The toughest hitters in the Phillies’ lineup — Harper and Kyle Schwarber — are lefties, and against them Gore was almost exclusively fastball-slider. For righties, he went fastball-cutter-curveball-changeup.

The results weren’t quite as spectacular, but Gore kept the Phillies in check. Philadelphia’s four right-handed hitters didn’t put a single secondary pitch in play and whiffed three times at six cutters.

All told, Gore got 20 whiffs on 50 swings out of 93 total pitches. There’s not too much to compare that to so far this year, so let’s go back to 2024, when there were 4,983 individual pitcher outings of 50 pitches or more between the regular season and playoffs. Out of those nearly 5,000 outings, Gore’s Opening Day start would’ve been tied for 108th in ratio of whiffs to total pitches — that’s the top 2.2% of the sample. Change the denominator to called strikes plus whiffs and the results are about the same — Gore’s start would’ve been in the top 2.4%.

As effective as Gore’s slider was, the best way to understand his great Opening Day start is by how he controlled the strike zone. Put simply, pitchers want hitters to take pitches in the strike zone and swing at pitches outside the zone; that’s why they bother spinning and curving and sliding the baseball in the first place.

Let’s compare Gore to another left-handed ace who started Thursday: Blake Snell. Gore threw 93 pitches to Snell’s 92, and got an inning further into the game despite facing six fewer hitters. He threw 66 strikes to Snell’s 53, and allowed one baserunner to Snell’s nine. Snell threw 41% of his pitches in the zone (Jesus Christ), and got the Tigers to swing at 68% of the pitches inside the zone and 26% of pitches outside the zone.

That’s about normal; in 2024, the league-wide Z-Swing% was 66.0% and the league-wide O-Swing% was 28.6%.

Now, I’ll concede that the Phillies are one of the more aggressive teams in the league, and the shadows, and Opening Day jitters, and all that. But Gore threw 55% of his pitches in the zone, with a Z-Swing% of 65% and an O-Swing% of 40%. That’s the third-smallest gap of any outing in Gore’s career.

And if circumstances had more to do with this 13-strikeout performance than Gore, explain why the Phillies looked so happy when he got pulled. After failing to get a runner to second base in six innings against Gore, they homered twice in the first inning after he got pulled. In four innings against the Nationals’ bullpen, the Phillies struck out six more times, but they also added seven hits, six walks, and seven runs. (In mild defense of Washington’s bullpen, that includes the 10th-inning bonus runner, and a two-run triple by J.T. Realmuto that Dylan Crews got his glove on and dropped. It got scored a hit because everything gets scored a hit these days.)

Anyway, the Phillies wouldn’t have exploded like that if Gore weren’t doing something impressive. I’m not ready to anoint him as king of the no. 1 starters just yet, but I’ll absolutely be watching his next start.