There have been many exciting MLB debuts this year such as Steven Matz, Aaron Nola, and Noah Syndergaard, and the latest is Yankee prospect Luis Severino. Through the minor leagues, Severino posted superb numbers, featuring a 1.91 ERA in AAA and 98 strikeouts across all minor league teams in 2015. He has been praised for an electric Fastball similar to Yordano Ventura‘s and Pedro Martinez’s with a plus Slider and Changeup to back it up. I was eager to see the 21-year-old’s stuff with my own eyes for his first game in the bigs, and I sat down Wednesday night to see if he was worth the hype. This is Luis Severino‘s GIF Breakdown of that start.

As always, let’s begin by looking at his strikezone plot for the evening:

This plot tells us quite a bit about Severino. The first thing you’ll notice is that he focused glove side for most of the night. The reason is because he wanted his Cutter (i.e. Slider, we’ll go more into this later) either jamming left-handers or darting off the plate to right-handers. It makes for a great 1-2 punch with his 96+ MPH Fastball that prevents hitters from recognizing the ball’s trajectory. Severino also primarily stayed low in the zone – a habit that keep up a solid 45.5% groundball rate. His Changeup rarely floated high, and when it missed, it missed low off the plate. It’s a promising plot, and while variety will be helpful in future outings, it makes sense for him to stick to his groove for the first game on the hill.

We also got a great slow-motion shot of Severino’s delivery:

I want you to focus on Severino’s front foot as it strides toward the plate. Normally, pitchers will glide out and fall heel-toe as they push off the rubber. Severino instead adds a small hop with his foot before landing, giving his arm a little more time to elevate and get on top of the ball for release. It’s a minor tweak that makes a big difference.

Now let’s take a look at his pitches individually across the evening:

Note: Usage percentages and velocity numbers represent Wednesday’s game only and were taken from Brooks Baseball.

Fastball: 54.3% thrown, Average 96.5 MPH, Max 98.3 MPH

It’s easy to pick up that Severino has a top-notch Fastball. He averaged a blistering 96.5 MPH across the night (which may have been a product of “debut adrenaline”) while pairing it with some excellent locations. For example, check out 1-1 heater to Brock Holt:

Despite focusing glove side for most of the night, Severino was also able to get inside on right-handers as he climbed back into a 1-0 count with this Fastball to Hanley Ramirez:

Though Severino was was able to hit his spot inside to a lefty – like in the Holt GIF – he had difficulty hitting the outside corner. Watch here as he tugged two straight Fastballs to David Ortiz:

Yes, there are two different pitches in that GIF. Severino was unable to make an adjustment and replicated the mistake, a small sign of immaturity that wasn’t present in the debuts for Noah Syndergaard and Aaron Nola. Severino also struggled getting ahead of batters quickly, and was only 27.8% on first-pitch strikes (5/18). His Fastball has a lot of potential and he was able to trust it deeper in counts, but the ability to pound the strikezone effectively with Fastballs is critical for success. Hopefully Severino can fix this in his next outing.

Slider: 27.7% thrown, Average 90.3 MPH, Max 92.5 MPH

I’m a firm believer that Severino throws two different Sliders – one that acts more like a Cutter, and one that is your traditional Slider. In the first few innings, Severino focused more on getting Cut action, trying not to miss bats but instead generate weak contact. It earned him many foul balls and quick outs like this one to Pablo Sandoval:

Notice how the pitch had subtle movement down and in, and didn’t have significant drop. This lack of movement deceived Pablo into thinking it was a straight Fastball, and the slower speed and small late bite was enough to induce a grounder to Mark Teixeira. Sometimes, just the change of speed was enough. Just watch how far Mike Napoli was in front of this 90 MPH pitch:

As the game developed, we started seeing more of the big break when JR Murphy put down three fingers. Compare the previous two GIFs with this pitch to Ramirez:

There’s the big break that we are accustomed to from a typical Slider, and it’s a deadly pitch that will constant miss bats. He was also able to punchout Holt with nearly the same pitch:

A major difference between his Slider and Cutter is their respective command. Severino was able to throw the Cutter for strikes effectively, and used it often to make up for missed early Fastballs. His Slider found itself in the dirt often:

Just like with his Fastball, Severino would benefit greatly by adding the ability to throw his Slider for strikes. While his Cutter is an effective tool, it doesn’t have the same break to keep batters consistently off-balance by the third at-bat. Mixing the pitches up more consistently should provide great results for Severino moving forward, regardless of command development.

Changeup: 18.1% thrown, Average 89.5 MPH, Max 90.8 MPH

The gameplan looked to be simple. Throw Fastballs and Cutters the first time through the lineup, then switch to Sliders and Changeups the second time. It’s a bit of a surprise given that Severino has an above-average Change that he waited so long to use it prominently. When it did show itself in the later innings, Severino was able to confuse batters into hitting a weak foul ball:

Or induce a soft grounder:

The most intriguing part is the location of these pitches. While both are down in the zone, they ended up near the middle of the plate and still gave batters a headache. Severino already has a deadly tool in his hands, and better locations in concert with a slight increase in Changeup usage can make for a smooth time on the hill.

Final Line: 5.0 IP, 1 ER, 2 Hits, 0 BBs, 7 Ks.

I was very impressed with what I saw from Severino. The Red Sox lineup isn’t one to impose fear these days, but Severino was able to climb back when behind in counts and make good pitches when he needed to. He has a lot of upside with his blazing Fastball, but he needs to command it better early in at-bats and develop more confidence throwing to his arm-side. Severino has an above-average mix of pitches to complement his heater, including a Cutter/Slider combination that can feature a big break or a tight late bite. His Slider is more prominent and will be a more potent weapon in the long run, while his Cutter can generate outs quickly when needing to limit his pitch count. Hopefully his Changeup will make a more consistent appearance in future outings as it has great horizontal ride and depth mixed with solid command to keep the pitch deep in the zone.

Considering that Luis Severino is not on an innings limit, he will be slotted in the mid 40s next week on The List. If I see development in his Fastball command and a better mix of pitches, he could be cracking the Top 40 quickly.

As always, I’ll leave you with a pitch that encapsulates a heavy focus of our featured pitcher. Here Luis Severino spots a 96 MPH 1-2 Fastball in on the hands of Jackie Bradley Jr. for the strikeout: