On Thursday, August 21, in the ninth inning at Petco Park, Mason Miller threw a four-seam fastball at 103.5 mph against Byron Buxton of the Minnesota Twins. It was the fastest pitch thrown anywhere in MLB that night. Not a career record — that’s 104.5 mph, set in the 2025 postseason — but a reminder that the San Diego Padres‘ closer operates at a frequency almost no pitcher on the planet can match. The Padres won 6-2.
What 103.5 mph actually means in context
The MLB-wide average four-seam fastball velocity in 2026 sits at 94.7 mph for all pitchers, and 95.6 mph for right-handed relievers. Miller’s ninth-inning heater to Buxton beat that mark by nearly 8 mph. Only six pitchers in the entire league average 100+ mph on their four-seamer this season — and Miller leads that group at 101.5 mph.
That pitch also registered 14.7 inches of horizontal movement. This isn’t a flat, straight bullet thrown on pure bravado. It has life, and that makes it a whole different problem for hitters trying to pick it up out of his hand.
Buxton isn’t an easy out, either. He’s carrying an .864 OPS with 25 home runs this season and sits in the 92nd percentile in exit velocity on Statcast. The matchup had all the makings of a real test. Miller passed it the way he always does.
The closer San Diego got for almost nothing
Miller came to San Diego in a trade from the Athletics in July 2025, then signed for $4 million heading into 2026 — his first year of arbitration eligibility. Given what he’s done, that contract looks like one of the best bargains in baseball right now.
He leads the National League with 31 saves and owns a 0.84 ERA across 53.1 innings. His WHIP of 0.81 means fewer than one batter per inning reaches base against him. He’s struck out 98 batters while walking just 19 — good for the 100th percentile in strikeout rate on Statcast. According to ESPN, he has not allowed a single home run all season.
Statcast shows his average exit velocity allowed is 85.2 mph — the lower that number, the softer hitters are making contact — and his barrel rate allowed is just 3.6%, placing him in the 94th percentile in barrels avoided.
Thursday’s win over the Twins opened a three-game series between two clubs fighting for Wild Card spots. Miller walked in, closed it out, and walked off. Same as always.
The numbers behind the dominance
Miller’s full 2026 stat line from the mound:
- 51 appearances, 53.1 innings pitched
- ERA: 0.84 · WHIP: 0.81
- 98 strikeouts vs. 19 walks (48.5% strikeout rate)
- 31 saves
- xERA: 1.45 (expected ERA based on contact quality allowed)
- Average fastball: 101.5 mph with 2,528 rpm of spin
- Whiff rate: 47.1% of swings against him miss entirely
- Batting average against: .133
- Average exit velocity allowed: 85.2 mph
- Barrel rate allowed: 3.6%
How he ranks against the rest of MLB on Statcast:
- xERA: 100th percentile
- Strikeout rate (K%): 100th percentile
- Whiff %: 100th percentile
- Fastball velocity: 100th percentile
- Fastball spin rate: 96th percentile
- xwOBA against: 100th percentile
- Soft contact allowed: 97th percentile
- Barrels avoided: 94th percentile
- Hard-hit rate avoided: 98th percentile
