All the Numbers Behind Mason Miller’s Unhittable Streak As Team USA Goes for WBC Title

Miller is on one of the best runs we’ve ever seen from a reliever.

San Diego Padres reliever Mason Miller has been unhittable since September of 2025. | Sam Navarro-Imagn Images

Mason Miller has been one of baseball’s elite relievers since transitioning to the bullpen in 2024, but he has officially hit another gear.

The A’s shipped the 27-year-old to the Padres at the 2025 MLB trade deadline for an enormous package. After settling in, Miller has been unbelievably dominant ever since, including one of the best innings anyone has ever seen in the postseason against the Cubs. He has been downright unhittable since early September.

Perhaps I didn’t realize just how good Miller has been until Peter Appel posted the following statistic: Since Sept. 8, opposing hitters are not 0-for-50 against Miller with 39 strikeouts. Those numbers include the postseason and World Baseball Classic.

Sure enough, the numbers check out.

From Sept. 8 until the end of the 2025 season, Miller pitched in nine games, throwing 10 shutout innings. He didn’t allow a hit, while striking out 21 batters and walking four. Opposing batters were 0-for-30 against him. His FIP was a hilarious 0.14.

In the wild-card round against the Cubs, Miller pitched in two games, going 2 2/3 innings. He allowed no runs, no hits and struck out eight. He hit one batter, but opposing hitters went 0-for-8 against him. Yes, that’s right, other than hitting a guy, everyone he faced struck out.

So far in the 2026 World Baseball Classic, Miller has been on the mound in four games, pitching a total of four innings. He hasn’t allowed a run or a hit, though he does have two walks. Opposing hitters are 0-for-12 against him, and of the 12 outs he’s recorded, 10 have been strikeouts.

In fact, entering Sunday night’s matchup with the Dominican Republic at the World Baseball Classic, 19 of the previous 20 outs Miller had gotten were strikeouts.

While those numbers are incredible, Miller’s dominance goes back even further. He hasn’t allowed a run since Aug. 5 of last year, when Diamondbacks DH Lourdes Gurriel Jr. took him deep at Chase Field.

Since that time, Miller has pitched in 26 games, throwing 28 innings. As stated, he hasn’t allowed a run, and opposing batters are 4-for-85—which is a .047 batting average—with four singles, 11 walks, and 60 strikeouts.

This might be the best run we’ve ever seen from a high-leverage reliever.

Mason Miller’s pitching arsenal

While Miller is famous for his four-seam fastball that averages 101.2 mph and can hit 105, it might actually be his second-best pitch. As crazy as it may seem, opposing hitters have a much more difficult time with his slider.

Miller throws his breaking pitch about 45.6% of the time, and it is devastating. It has a spin rate of 2,396, comes in at an average of 87.8 mph, and can look like his fastball until it dives out of the zone at the last second.

Opposing batters hit .108 off Miller’s slider in 2025, with an xSLG of just .198. The pitch had a wOBA of .112. They didn’t do much better off the fastball, hitting .168 on it, with an xSLG of .362, and a wOBA of .317.

Both pitches out elite, but the slider is his better offering. How good is it? On September 3 of last season, Miller tossed an immaculate inning against the Orioles, and all nine pitches he threw were sliders.

Check it out:

Miller also has a changeup that flashes plus, but he only threw it 22 times in 2025. I’d expect to see far more of it in 2026.

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