GIF Breakdown: Mason Miller’s MLB Debut in 31 GIFs

A breakdown of Mason Miller's Major League debut.

Debuts from pitchers that burst onto the scene out of nowhere are extra enjoyable. That’s the case for Oakland’s number three prospect (according to MLB Pipeline), Mason Miller, as he was an unknown arm in a thin A’s system before 2023, where a couple of starts in the minors and a quick call-up earned him recognition from prospect experts and fantasy managers alike. There’s not much to root for in Oakland right now, and as a resident of the Bay Area, I can attest to that, but he is a much-needed shining ray of hope in the organization.

Miller wasn’t a household name prior to this year for two reasons. One: he wasn’t taken notably early in his draft class and was drafted in recent years (leaving less time in the minors for his name to popularize), going off the board in the third round as the number 97 overall pick in the 2021 draft. Two: He struggled with injuries throughout his minor league career, appearing in just eight games (20 IP) from 2021-22.

However, the 24-year-old’s first two starts in 2023 (one in AA and one in AAA) have ratcheted up the hype to unforeseen levels. Across 8.2 innings in those starts, Miller surrendered just two runs, but the most notable aspects of his time on the mound were his 19/0 K/BB ratio and his undeniably overwhelming arsenal. That armament of pitches is what forced prospect lists’ hands to jump him in their pre-season rankings.

The 6’5″ right-hander features one of the best fastballs in the minors and pairs it with a wipeout slider. The heater, which supposedly hits triple digits on a regular basis (it averaged 100 mph in his AAA start), earned a 70 grade from both MLB Pipeline and FanGraphs. The slider earned his second-best scouting grade at 55 on both publications as well. He also features a developing changeup and debuted an underrated cutter this season.

The hype is certainly at its peak, but can a successful debut with everybody watching make the fireballer an even more coveted waiver wire add this weekend? Let’s watch Miller light up the radar gun!


First Inning

Mason Miller Pitch #1

Right off the bat, we get to see Miller reach triple digits as he showed off his go-to pitch to begin his major league career. Technically, it was only 99.7 mph according to Statcast, but with rounding, it counts. Miller makes it look easy and I’m pumped to see him get such a high-velocity pitch in the zone.

Mason Miller Pitch #2

His second pitch also hits 100 mph but it’s not framed well by the catcher and results in his first ball.

Mason Miller Pitch #3

We get triple digits for the third time, but Nico Hoerner is able to handle this one and bashes it to left for a leadoff single. Not the best way to start off your major league career, but it allows us to see how he deals with adversity and what he looks like out of the stretch. It’s interesting to see Hoerner get to 100 mph inside like that, but it can be explained by him being on fire in recent days and modern hitters being able to handle high-velocity pitches.

With Dansby Swanson coming up, we get our first look at Miller’s slider.

Mason Miller Pitch #4

The location isn’t great but we can see that the pitch has plenty of movement and has a large gap in velocity (~15 mph) from his fastball. If he can deliver more competitive offerings with the slider, it should play fantastically off his heater.

The next pitch is a fastball up and in that’s fouled off to bring the count even. On 1-1, Miller misses away with a fastball putting him behind in the count.

Mason Miller Pitch #7

The big righty gets back on track, busting Swanson up and in again with 100 mph and getting a positive result in the form of a routine popup to the second baseman for his first out in the majors. Keeping that pitch up in the zone and inside to both righties and lefties will generally have beneficial outcomes.

Now facing Ian Happ, we get a glimpse of Miller’s cutter.

Mason Miller Pitch #8

It comes in hot at 95 mph and is placed well, in on Happ’s hands. We only get a peak at the pitch as Happ lines it to the second baseman who catches an aggressive Hoerner too far off first for a double play.

It’s an abrupt ending to Miller’s first MLB inning, but it keeps his pitch count down and helps him live to see another frame.


Second Inning

The second inning kicks off with former MVP Cody Bellinger striding to the plate.

Mason Miller Pitch #9

This is a very uncompetitive miss. Bellinger doesn’t think about swinging for one second and the pitch doesn’t set up a subsequent pitch effectively. Clearly, Miller’s stuff is great, but if he wants to maximize his success on the mound, he’ll have to make every pitch count.

Mason Miller Pitch#10

Making up for his uncompetitive miss, he induces his first whiff of the night on a beautiful low slider.

The next pitch is another slider that just misses off the outside edge but he evens up the count with a 100 mph fastball down the middle. At this point, Bellinger seems off balance and it’s his best guess what pitch is coming next.

Mason Miller Pitch #13

Miller goes right back to the fastball, placing it perfectly up in the zone at 100.2 mph, inducing his second whiff to earn his first career strikeout. I love the location of the pitch, and with that kind of velocity, there are very few hitters that can catch up to it. Bellinger fans a lot, but making your first punchout victim a former MVP is impressive nonetheless.

He starts the next batter, Edwin Ríos, with three straight fastballs of at least 100.5 mph. The first is on the inside edge but is fouled off. The next two both miss too high out of the zone. He turns to the high fastball one more time and gets it close enough to the top of the zone to garner a swing and another foul ball.

Mason Miller Pitch #18

With the count even, Miller catches Rios off guard with a slider in the zone for his second strikeout. It’s actually a hanger right down the middle, but after four straight heaters at 100 mph, the batter is unable to react to the spinner. Understanding when to change speeds will be important for Miller as it may dictate his success from batter to batter.

The third batter of the inning is current home run co-leader Patrick Wisdom who gets the opposite treatment.

Mason Miller Pitch #19

Miller starts Wisdom off with three sliders and it goes exactly to plan. The first one forces an ugly check swing that is ruled a strike.

Mason Miller Pitch #20

The second one freezes Wisdom, landing for a called strike. At this point, it’s obvious Wisdom is geared up for the heater and seems to be getting fooled by the slider as it comes out of the same tunnel as the fastball before falling off the table. Miller recognizes that Wisdom is cheating on the hard stuff and triples down on the slider. He misses away and decides to switch things up by dialling up the heat.

Mason Miller Pitch #22

He doesn’t quite put it where he wants to but it’s a competitive miss and he reaches over 102 mph. It results in an awkward swing from Wisdom who’s barely able to foul it off and clearly looks uncomfortable at the plate.

That heater at 102 is followed up by another fastball that misses too low, this one reaching 102.5 mph according to Statcast. That would wind up being his highest velocity on the day and it’s quite impressive for a starter to be able to unleash heat of that calibre. It’s clear that if Miller doesn’t work out as a starter, he’s got a potentially bright future as a shutdown closer.

Mason Miller Pitch #24

Tripling up on the fastball, Miller finally gets this one up in the zone and coaxes a swing-and-miss from Wisdom. After a quick first, Miller strikes out the side in the second.


Third Inning

Facing the bottom of the order for the first time, it’s important to keep an eye on how Miller attacks the hitters that pose less of a threat. As long as he keeps his foot on the pedal and continues to dominate, we should feel good about his approach.

With Eric Hosmer up, Miller misses way out of the zone with two fastballs – one way outside and one so far low and in that the catcher misses it and it hits the backstop. That’s a quick and easy 2-0 count for Hosmer on two uncompetitive pitches.

Mason Miller Pitch #27

Luckily for Miller, he gets the next one in the zone and gets an aggressive Hosmer to pop out to the shortstop. It’s a positive outcome, but uncompetitive misses like the ones that started this at-bat are what force pitchers to hit the zone at times when hitters are expecting and prepared. This could’ve been much worse had it been a different player at the plate.

Contact king Nick Madrigal is next and he looks at a fastball down the middle for strike one. It’s followed by three more heaters – one that just misses up and glove-side, and two that are up in the zone but fouled off.

Mason Miller Pitch #32

Miller recognizes that Madrigal is not having any trouble making contact with the fastball so he slows it down. He leaves the slider up and Madrigal fights it off, but Miller is helped out by the expansive foul ground in the Coliseum. It gives the right fielder enough room to make a nice running catch for out number two.

With the nine-hole hitter, Tucker Barnhart, at the plate, Miller starts him off with some secondaries. The first one is a cutter at 96 mph that misses low and in. So far we’ve only seen that pitch twice and both times it was against a left-handed hitter. That should indicate that it’s a pitch he wants to use to bust lefties inside. The second pitch is an awful slider bounced five feet in front of the plate. Now, down 2-0, Miller goes back to his bread-and-butter, inducing two fouls balls on back-to-back high heaters.

Mason Miller Pitch #37

With two strikes, Miller goes with the backfoot slider and nearly coaxes a swing from Barnhart. It’s a great option if executed correctly, but Miller takes it too literally, hitting Barnhart on his left toe. An unfortunate outcome, but it wasn’t a particularly wild pitch or a poor pitch decision. He made it nearly a full turn through the lineup without allowing a baserunner before butchering that at-bat.

That turns the lineup over for the first time and brings Hoerner back to the plate. He loses control of a fastball up and in, forcing Hoerner to turn away to avoid a mouthful of baseball. One thing I can observe from watching the first half of Miller’s start is that he sometimes loses control of his pitches when he’s not focusing on executing them. Obviously, he’s out there trying to throw every pitch for a strike, but there are times when his mind is wandering or focused on the wrong thing and it results in poor execution. It’s the perils of being a young pitcher with jitters in your major league debut, so let’s hope it’s something we don’t have to worry about in future starts, but it does explain why sometimes he exhibits exceptional command and others he’s as wild as a mustang.

He gets Hoerner to two strikes after a sequence of fastballs and sliders. The first is a fastball for a called strike that clips the inside edge, the second is a slider that misses wide, and the third and fourth are fastballs at the top of the zone that hit foul.

Mason Miller Pitch #43

A well-placed slider outside catches Hoerner off balance and results in a weak groundout to third. Miller has now survived one turn through the lineup without allowing a run and has yet to break a sweat.


Fourth Inning

Swanson leads off the fourth and Miller does something that I wish he’d do more.

Mason Miller Pitch #44

He flips a slider in the zone, stealing free real estate and a strike. The Cubs hitters all seem so geared up for 100 mph that he could be stealing a lot more strikes by just tossing the slider in the zone. Of the 13 sliders he’s thrown at this point, just two resulted in contact, and both were weakly put in play for outs. Not only would Miller get more strikes and increase the effectiveness of his slider, but I think it would also help the fastball play up more and keep the hitters guessing.

Miller turns to the slider again but misses way out of the zone as the ball skips to the backstop.

Mason Miller Pitch #46

He focuses up and blows 100 mph at the top of the zone. It overpowers Swanson somewhat as he’s barely able to foul it off. Realizing this, he goes right back to the heater but misses high. He then switches it up with a slider that nearly hits Swanson in the head but breaks enough to avoid him – altogether an awful pitch.

Mason Miller Pitch #49

Now with the count full, he goes back to the high heater and nearly gets a swing but Swanson holds up. The result is Miller’s first walk. I’m a bit surprised it took this long, to be honest. Given his stuff and unspectacular command grades, I would’ve expected him to have a hard time throwing strikes. Additionally, given the plethora of uncompetitive misses we’ve witnessed thus far, I would’ve expected more three-ball counts. However, he’s done a good job of living in the zone when he does control his pitches and this seems like a blip on the radar. Let’s hope it doesn’t lead to an unravelling.

With the middle of the order due up and the leadoff man on, this will be a test of Miller’s competitive will and his mental fortitude. He starts Happ off with a heater for a called strike and quickly gets it to 0-2 by getting away with a fastball down the middle that Happ fouls off. The ensuing pitch is a spiked slider that gets away from the catcher, allowing the runner to advance to second.

Mason Miller Pitch #53

Taking advantage of the mistake, Happ takes a middle-middle slider to the right-center field gap for a run-scoring double. It’s the first run levied against Miller and now he’ll have to contend with another runner in scoring position with still nobody out.

Bellinger is overwhelmed by a fastball on the first pitch to him, lays off on a heater low and in, and then whiffs on another heater to put him in a hole. Miller is just dominating him with velocity.

Mason Miller Pitch #57

The catcher sets up outside but Miller misses his target. This is what I mean by a competitive miss. He accidentally paints the low, glove-side corner and sends Bellinger packing for his fourth strikeout. It gives him the confidence to escape this jam without further damage.

Rios steps back up to the plate and we finally see Miller turn to his changeup.

Mason Miller Pitch #58

It’s difficult to make any assessments of the offspeed pitch based on this offering. He clearly doesn’t have the feel for it here after not turning to it across 50+ pitches. A nice play by the catcher keeps the runner on second. A second-pitch fastball is fouled off before Miller turns to his cutter, which I believe to be his preferred third option.

Mason Miller Pitch #60

That’s a gorgeous pitch. Placed perfectly with productive velocity and it induces a whiff. I think he needs to turn to this pitch more often because it does such a good job of jamming lefties and it seems as though he controls it well. The lack of usage may be a case of the Cubs not featuring a lefty-heavy lineup, so in future starts it may be more of a key component of his arsenal.

Mason Miller Pitch #61

The final pitch of the at-bat is a fastball down the middle that Rios, fortunately, rolls over, hitting a routine grounder to the second baseman. Miller is now one out away from escaping the jam.

He misses high with two fastballs to Wisdom before getting one in the zone for a swing and miss. He then paints 101 on the outside edge to set up a big pitch.

Mason Miller Pitch #66

The big righty dials up 101 mph and gets Wisdom on a check swing and a miss for his fifth K to get him out of the inning.


Fifth Inning

At 66 pitches and facing the bottom of the order, manager Mark Kotsay lets Miller take the mound to start the fifth.

Back-to-back fastballs to Hosmer sets the count even at 1-1. Then, a high cutter lands in the zone for a strike to quickly make it 1-2. However, he fails to put him away, missing up with a four-seamer and low and in with a cutter to bring the count full. Hosmer stays alive with a check swing foul ball on a nice cutter up and in to set up another decisive pitch.

Mason Miller Pitch #73

It’s an unlucky break for Miller as he forced Hosmer to chase and got a weak grounder. Diaz should’ve taken his time here as Hosmer isn’t known for his speed, but regardless, this is a play that is made most of the time. Now Miller is stuck with a runner on first after wasting seven pitches on Hosmer. The worst part is that this play was ruled a single, which seems incredibly unfair to the rookie.

Madrigal is next and the sequence Miller goes to is interesting. He gets a foul on a heater up and away to kick off the at-bat.

Mason Miller Pitch #75

This offering is rare not only because it’s the only cutter he’s thrown to a righty, but also because Madrigal never swings and misses. It’s suggestive of the notion that Miller should turn to the pitch more often in general, even to righties.

Madrigal fouls off the next two pitches – a slider out of the zone and a fastball away. I loved the sequence to start this at bat. Miller went away, away, away, reducing the velocity on each successive pitch and throwing the ball further out of the zone each time. I think it’s a plan that could work if properly executed in future starts.

Mason Miller Pitch #78

With two strikes, Miller struggles to put Madrigal away and leaves a cutter over the plate. It’s hit to right, putting runners on the corners with nobody out. It’s clear he’s starting to get tired, but the velocity is still there. Can he bear down and finish strong as he nears his pitch limit?

He tosses two four-seamers to Barnhart. The first one misses but should’ve been a strike had the catcher framed it better. The umpire makes up for the missed call by awarding Miller a called strike just off the inside edge.

Mason Miller Pitch #81

I’m sure it’s not the result he wanted, but he gets Barnhart to hit a sac fly. It gets Miller another out on his box score but also tacks on another run (that should’ve been unearned). At 81 pitches, the manager calls on the bullpen and Miller exits to a standing ovation from the small crown in Oakland.



Final Line: 4.1 IP, 4 H, 2 ER, 1 BB, 5 K – 10 Whiffs, 27% CSW, 81 Pitches


Pitch Type Count % Called Strikes Whiffs CSW% Zone% Max Velo Min Velo Avg Velo
4-Seam Fastball 51 63% 8 5 25% 59% 102.5 mph 96.6 mph 99.4 mph
Slider 18 22% 3 2 28% 33% 88.7 mph 85.5 mph 87 mph
Cutter 11 14% 1 3 36% 55% 97 mph 92.4 mph 95.1 mph
Changeup 1 1 0 0 0% 0% 92.3 mph 92.3 mph 92.3 mph
Total 81 100% 12 10 27% 52% 102.5 mph 85.5 mph 96 mph


It may not have been the earth-shattering start that puts Miller’s name on the map, but it was an exciting and successful debut nonetheless. Miller displayed a premier fastball and paired it nicely with effective secondaries. There’s clearly some work to do, but the stuff is undeniable.

The heater should always be elite given its velocity and Miller’s intent to pepper it at the top of the zone. It’s difficult for hitters to catch up to it there, and when they do, they can’t do much with it. The slider is a great change of speeds and its movement and tunnelling with the fastball makes it an effective pitch when thrown near the zone. The cutter is a surprisingly underrated offering that jams lefties and could be a weapon versus righties if used in the correct way. The changeup is basically nonexistent, but we can blame that on him not having the feel for it in this one.

Overall, it’s a sufficient arsenal, but the execution and usage require work. Far too often, Miller lost focus and flung fastballs far from the zone. I labelled them uncompetitive pitches because they’re basically waste pitches and don’t do anything other than give the batter an advantage. The thing is, he also did this with more than a few sliders and it made for a frustrating watch as he would unnecessarily fall behind in counts or fail to put batters away because he wasn’t living anywhere near the zone. I’m enamoured with the intent to blow 100 mph at the top of the zone and drop sliders in at the bottom of it, but it won’t work unless he’s living in and around the zone. With the stuff he has, nobody’s touching it.

In terms of usage, I’d love to see Miller utilize his secondaries more often. Obviously, that fastball is amazing and it’s his defining pitch, but it would perform even better if hitters weren’t always expecting it, seeing it more than 60% of the time. I’d love to see him use the slider not only to get whiffs later in counts but also to steal strikes early on. The cutter could also be used to steal strikes and to keep hitters off balance. If he ever finds his changeup, I think it would be a great weapon as a whiff pitch against lefties. All of this would help him get even more whiffs and called strikes on his fastballs as hitters remain off balance and continue to guess what’s coming next.

It’s all reminiscent of Hunter Greene. The big fastball, the sweeping slider, the lack of control. Greene has morphed into an ace by focusing on his plan of attack, which Miller seems to have an understanding of. His needs refining and better execution, but at least it’s there. The biggest parallel is that they both rely on a fastball that is fast but might be too hittable. Modern major league hitters are prepared and have the ability to consistently catch up with triple digits, so velocity alone won’t take anyone down. We saw throughout this game that the Cubs were geared up for the heater and were able to handle it until he started changing speeds. This is what leads me to suggest that he takes the Greene path, turning to his fastball less often to increase its effectiveness.

Miller’s got a bright future ahead of him thanks to his unhittable stuff. Based just on that, I’d suggest that he’s a pickup in 12-team mixed leagues to at least see what he does in his next turn. He’s got a guaranteed spot in the rotation and will take on the Angels next time – not the scariest matchup but still a test. What has me hesitant to award him the designation of must-roster is his lack of polish and his position on the worst team in baseball with terrible run support. There won’t be many wins coming his way and he’s still a young pitcher that is sure to encounter plenty of struggles. That being said, there aren’t many starters pumping 100 mph with serviceable secondaries and a solidified role, so he’s worth the risk. Miller’s also just a lot of fun to root for and to watch. Let’s see how he handles the two best players in baseball next.

Photo by Bob Kupbens/Icon Sportswire | Adapted by Justin Paradis (@JustParaDesigns on Twitter)

Jake Crumpler

A Bay Area sports fan and lover of baseball, Jake is a graduate of the University of California, Santa Cruz with a B.A. in English Literature. He currently writes fantasy articles for Pitcher List, is the lead baseball writer at The Athletes Hub, and does playing time analysis at BaseballHQ. Some consider his knowledge of the sport to be encyclopedic.

One response to “GIF Breakdown: Mason Miller’s MLB Debut in 31 GIFs”

  1. theKraken says:

    Hunter Green is not an ace. He is a perfect example that there is no such thing as untouchable stuff.

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