Mason Miller: Champ or Chump for Fantasy Baseball?

April 25, 2023

Is Mason Miller a fantasy baseball sleeper, bust, or neither? Is he a flash in the pan or will he thrive? Rick Lucks's deep dive into Miller's 2023 fantasy value.

Starting pitchers with electrifying stuff keep getting called up, with Mason Miller and Logan Allen the most recent examples. Miller has been somewhat polarizing in the fantasy community, with some drooling over his raw stuff while others don't want an Oakland (Las Vegas?) Athletic under any circumstances.

Miller hasn't thrown more than 7 IP at a single stop in his MiLB career, so he's a true wild card. That said, he's also struck out 51.5% of the batters he's faced as a professional. He looked good at the Arizona Fall League last season as well, pitching to a 3.24 ERA with 20 strikeouts in 16 2/3 IP.

The upside is tantalizing, but it's difficult to know what to expect with so little data to work from. Let's try anyway. Here is a deep look at the fantasy prospects of 24-year-old Mason Miller for 2023:

Why Hasn't Mason Miller Pitched That Much?

The first question we should be asking is why Miller has zero MiLB track record at age 24. A diagnosis of juvenile Type-I diabetes in 2018 is one of the primary culprits. He only weighed 150 pounds before finally finding a strength and conditioning program that worked for him and is now up to an athletic 220.

Miller was also drafted out of college, meaning that his career started later than a high schooler normally would have. Sadly, Miller sustained a scapula strain in his right (pitching) shoulder that kept him out of action until August last season, at which point he didn't have time for "Spring Training" to ramp up his workload. The result was a handful of short starts that the A's made even worse by promoting him aggressively, giving us minimal information.

What Do Scouts Say About Mason Miller?

Scouts love Miller's fastball and believe in his slider as a strikeout pitch as well, so scouting reports on him are generally favorable. FanGraphs and MLB Pipeline give Miller's fastball a 70 on the 20-80 scouting scale, and both outlets grade his slider at 55 (FanGraphs sees that going to 60 in the future).

Miller's third pitch is a change that MLB Pipeline believes "could still use some developing." However, FanGraphs grades it at 55 with 60 potential in the future. MLB Pipeline is much higher on Miller's control though, grading it at 50 whereas FanGraphs sees 30 command with 40 potential in the future.

The result is a bizarre situation where FanGraphs ranks Millers as the 101st prospect in the game but failed to put him on their Oakland list while MLB Pipeline has him as the third-best prospect in Oakland's system but excluded him from their overall list. FanGraphs lists his ETA as 2025, suggesting that he's also a fantasy option well ahead of schedule.

Exploring the Big League Debut of Mason Miller

Miller was solid in his first MLB start, going 4 1/3 IP with 5 Ks, 1 BB, 4 H, and 2 ER (4.15 ERA) against the Cubs. He threw a total of 81 pitches, with his primary weapons being his fastball, slider, and cutter. He threw one pitch that was classified as a change, which we'll ignore.

Miller's fastball was as advertised, averaging 100 mph while touching 103 on the gun. It also had an above-average spin with 2,400 RPM and performed well with a 9.8 SwStr% and 52.9 Zone%.

His slider wasn't as effective by the metrics though. Its 2,432 RPM spin rate was barely higher than his fastball, and plus breaking pitches routinely exceed 3,000 RPM. The Cubs weren't especially fooled by it either, as the pitch only had an 11.1 SwStr%, 33.3 Zone%, and 25% chase rate. Still, scouts uniformly love it so maybe he just didn't have a feel for it that day.

Miller's cutter isn't mentioned in the scouting reports and allowed a .667 average in his big league debut, but it also posted 27.3 SwStr%, 63.6 Zone%, and 75% chase rate. It certainly flashed potential though may not be a finished product.

Honestly, the most important part of the start might be the 81 pitches thrown. Most of Miller's detractors say he won't pile up enough innings to record wins or quality starts, but throwing over 80 pitches in his first outing suggests that Oakland will let him get to the 90-100 range eventually.

His MLB Pipeline scouting report also says, "There's no question Miller can throw a bunch of strikes with his big arm, and his 6-foot-5, 220-pound frame seems durable enough to hold up as a starter." Sounds promising for his immediate future as a starter, no?

The Verdict on Mason Miller

The other major indictment of Miller is that his supporting cast is beyond terrible, and that's true. However, his home park is an upside to pitching in Oakland. The Coliseum has absurd amounts of foul territory that increase foul outs and lower BABIP, so Miller's mistakes may not be punished as heavily as they would be elsewhere.

Projection systems are all over the place on where they see Miller's performance. Steamer LOVES him, projecting a 32.9 K%, 7.6 BB%, and 2.92 ERA. THE BAT is less enthused, projecting a 26.6 K%, 8.6 BB%, and 3.79 ERA. ATC doesn't like Miller at all, forecasting a 22.4 K%, 8.5 BB%, and 4.44 ERA. Which to believe is anybody's guess.

In fantasy, Miller is best seen as a high-risk, high-reward lottery ticket. He should be rostered by someone in most leagues, but the team doing so should be one trying to make things happen after a sluggish start rather than the manager who's currently in first place. His 35% roster rate is currently way too low, so let's call him a Champ.

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