The (Very) Early Returns on Luis Severino
The Yankees’ rotation has been scrutinized, analyzed, and generally evaluated as thin and weak when compared to other World Series rosters such as the Astros and the Dodgers. Certainly, the rotation had its struggles throughout the 2019 season, and the lack of depth in the rotation has been clear at various times throughout the year. Despite the performance of the starting rotation for much of the season, the Yankees have been publicly optimistic about the pitching staff’s potential for success in October. Some of that is the natural optimism all good teams espouse to the media, but some of that optimism is the realization of the return of a lost asset: Luis Severino. Of all of the injuries the Yankees have faced this season, it can be argued that the most important injury this season was to Luis Severino. Severino came into 2019 as the formidable ace of the staff, and the Yankees have been without him for the entire regular season prior to the final weeks of September. Few teams are capable of winning consistently despite the loss of the ace of the pitching staff, yet the Yankees have prevailed, and look to be that much stronger now that Sevy has returned.
Despite the optimism surrounding Sevy’s return, there were significant questions about what Severino would look like when he finally entered an MLB game this year. For one, his injuries were all sustained in his pitching shoulder and pitching lat. Additionally, Severino had multiple setbacks during his rehabilitation program. As good as Severino has been the last two years, it was fair to wonder what he would look like. We are working with an admittedly minuscule sample size, but the early performance has been outstanding.
Severino has thrown 9 innings in two starts since his return, striking out 13 batters while allowing just 5 hits, 2 walks, and no runs. As electrifying as the results have been, the caveat is that both starts came against weak offenses currently employed by the Angels and the Royals. What do the underlying metrics tell us about how real Severino’s performance is since his return? I am willing to throw some of my usual caution and skepticism to the wind regarding the sample size, and I think the metrics tell us that this version of Luis Severino is every bit as dominant as the eye test would lead us to believe.
Let’s start with the adjustment Severino has made to his pitch usage. Prior to this season, Severino had settled in as a guy who threw his four-seam fastball roughly 50% of the time, while relying heavily on his slider as his primary secondary offering, throwing it almost 35% his pitches, while showing his change-up on just 13% of his pitches. 2019 Severino has been a little different. Check out the difference in Sevy’s pitch mix this year as compared to 2017 and 2018, courtesy of Brooks Baseball:
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For a couple of years now, the Yankees have philosophically favored an approach that favors pitcher’s best secondary offerings over the fastball. Much like James Paxton recently, Severino appears to be shifting his pitch mix to work more traditionally, throwing his four-seam fastball close to 60% of the time. Severino’s increased fastball usage has come at the expense of his slider, which he has used on just 25% of his pitches, a 10% drop overall. This difference has also allowed Severino to throw more change-ups to offset his fastball, upping his usage of the pitch noticeably.
I view this change as positive. Severino has a high octane fastball that he is capable of blowing by even elite hitters. More importantly, I noted that increased fastball usage is allowing Severino to throw more change-ups. While popular perception is that Severino’s best secondary offering is his slider (and it is great!), most scouts and talent evaluators pegged Sevy’s change-up as a plus pitch and his best off-speed pitch when he was coming up through the minors. As good as Severino’s slider has looked, I’ve been most impressed by his feel for the change-up, and believe that a more balanced pitch mix will serve Severino moving forward.
Most of the baseball world wondered what Severino’s velocity would look like given the fact that his initial injury was to his shoulder, and he has not had a lot of time to build arm strength in game situations. Those concerns have mostly been quieted, although there is some noticeable differences in Sevy’s velocity. Take a look, courtesy of Brooks Baseball:
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Sevy’s fastball velocity is down a touch, but it still has elite zip. Most interestingly, Severino’s slider is down by more than 3 MPH this year from its historical velocity. Given the pitch’s movement and velocity separation from Severino’s fastball, I am not concerned about the drop in velocity on Sevy’s slider. That said, I wonder if the velocity drop is intentional. The ball is different this year, and we have seen multiple pitchers struggle with pitches like sliders due to the lower seams and harder ball. I have no evidence to support this, but my gut tells me that Severino is backing off of the slider a touch to maintain feel and control.
Overall, Sevy’s velocity is within range of his historical norms, and there is little cause for concern based on velocity,
Luis Severino is a power pitcher who is not necessarily known for his command. It is important to recognize the difference between control and command in this context; control is the ability to throw strikes, something that Severino has generally been able to do throughout his career, while command is the ability to locate the baseball both inside and outside of the strike zone strategically. Severino has historically relied more on pure stuff and less on command to dominate opposing hitters. However, the 2019 version of Luis Severino has shown a surprising amount of command. Check out the location heat maps for all of Severino’s pitches thus far in 2019, courtesy of Baseball Savant:
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These location heat maps are works of art. Sevy has worked his fastball up in the zone and to the corners, while spotting his change-up and slider low and occasionally just out of the zone. These locations represent perfect strategy for achieving strikeouts and ground balls. While Severino has not yet faced a formidable offense this season, his command combined with his stuff plays against any offense.
Swings, Contact, and Whiffs
Quite simply, a combination of the aforementioned factors have allowed Severino to thrive with regards to the swings opposing hitters have put up thus far. According to Fangraphs, hitters have swung at 36.3% of Sevy’s pitches outside of the strike zone, 6.3% more frequently than hitters have historically against Severino. This speaks to the command and stuff that Severino has shown thus far. Meanwhile, Fangraphs shows that hitters have made contact on a whopping 72.4% of swings on balls thrown outside of the strike zone against Sevy, more than 12% above historical norms. This helps explain the poor contact that hitters have made against Severino this year, putting up an average exit velocity of just 85.2 MPH according to Baseball Savant, well below average. When Sevy isn’t inducing soft contact, he is striking out 38.2% of batters faced.
Surely, the weak offenses Severino has faced help his dominant statistics somewhat, but the totality of what Severino is doing right with regards to velocity, command, and pitch usage have far more to do with his success thus far. Despite the small sample size, I think that the most dominant version of Severino has arrived just in time for the playoffs. I think the Yankees have good reason to be optimistic about at least half of the postseason rotation based on recent results, the return of Severino truly does mean the return of an ace.