The Yankees didn’t really know what they were getting when they signed a 17-year old Luis Severino as an international free agent out of the Dominican Republic in December 2011. The right-handed pitcher was a waifish 6’0″, 175lbs at the time, but tantalized scouts with a 91-92 MPH fastball that touched 95 on occasion.
Severino has grown physically since then, now standing at a strapping 6’2″, 215lbs with an impressive physical frame. The increased muscle mass added significant velocity to his fastball, which now averages 97 MPH and tops out in the low-100s. But Severino’s emotional and intellectual growth has been even more impressive, successfully completing the difficult transformation from ‘thrower’ to pitcher over the last two seasons.
Now, four months into the 2017 season and at a sprightly 23 years old, Severino is one of baseball’s best starting pitchers. As we’ll discover, Severino’s dominance stems from a robust skillset that excels in every category that matters in run prevention, including swing and miss ability, command, groundball tendency and batted ball authority. He is, in effect, the perfect pitcher.
The maturation process
Severino cruised through the Yankees’ minor league system with ease, posting a sub-3.00 ERA at every level of competition along the way. His plus-plus fastball velocity allowed Severino to dominate minor league hitters with little consideration for pitch mix or deception. Severino’s MLB debut in 2015, at a mere 21 years of age, went equally as smoothly, with a 2.89 ERA and 5-3 record across 11 starts.
It wasn’t until 2016 that Severino experienced the first real adversity of his professional career. Severino made the Yankees’ starting rotation out of spring training, but struggled to the tune of a 7.46 ERA over his first seven starts. He was subsequently demoted to AAA, where he pitched very well over 11 starts. Severino earned a promotion back up to the majors in late July, but struggled mightily soon after, giving up five earned runs in Boston on August 9th and seven against Tampa on August 14th. After another quick trip down to the minors, Severino was promoted again and finished the season pitching reasonably well out of the Yankee bullpen.
In search of guidance, Severino reached out to fellow countryman and Hall-of-Fame pitcher Pedro Martinez over the offseason. The two worked out together in Santo Domingo, Dominican Republic, with Martinez dispensing tips on how Severino should adjust his mechanics and refine his rhythm on the mound. While it’s difficult to know just how much Pedro’s advice meant in Severino’s turn around this season, the results are difficult to discredit.
One of the best pitchers in baseball
Severino wasted little time in proving his doubters wrong heading into 2017. He put up 20 strikeouts across 18 2/3 innings in spring training with a 3.38 ERA, good enough to lock down the fourth spot in the Yankees’ rotation to open the season. With his fastball velocity up almost 1 MPH from the previous season, as well as an improved changeup, Severino came out firing out the gate, with a 3.00 ERA and 8.3 strikeout-to-walk ratio across four April starts. While the K/BB ratio has eroded from elite to simply very good, everything else has stayed course, with Severino posting the fifth highest wins above replacement (WAR) per start in baseball this season. Take note of his WAR/GS compared to Clayton Kershaw, the pitcher with the best adjusted ERA of all-time – they’re nearly identical, with Kershaw’s 0.191 barely edging Severino’s 0.190.
Severino’s strong WAR performance is supported by across the board dominance in strikeouts, walks, batting average against and home runs against. His percentile, among MLB starters with at least 80 innings pitched this season, ranks 81st or higher in the following statistics: ERA, FIP, xFIP, K%, BB%, K-BB%, AVG and HR/9. What typically separates good pitchers from great pitchers is that the former usually excel in only one or two areas, whereas the latter do in three or four. Maybe the good ones get a lot of strikeouts and give up few home runs, but they also walk a lot of batters. Or they limit walks and restrict the hard contact that leads to high batting averages, but they don’t strike out many batters. The great pitchers combine strikeouts, plate command and weak contact into one package.
Strikeout ability and command
The first place to look when parsing through pitcher performance are strikeouts and walks. The pitcher controls these outputs more than any others, and as a result, they have the biggest determining factor in long-term success. As noted above, Severino’s 27.6% strikeout rate ranks in the 88th percentile among starters, which is obviously very good. But how does he manage that?
Severino’s most hallmark attribute is his fastball velocity. It started at 95.3 MPH on average in 2015, then went up to 96.1 in 2016 and is now a league-leading 97.3 in 2017 (to be fair, Noah Syndergaard would be first if he met the 80 innings cut off this season, but maybe that’s the reason he tore his lat). Not only is Severino’s velocity first, it’s first by a lot, a full 1.1 MPH higher than second place Gerrit Cole’s. The z-score on Severino’s fastball, which measures the amount of standard deviations his fastball velocity is above the league average in fastball velocity, is an astronomical 2.3.
Not surprisingly, this fastball velocity, to go along with a wipe-out slider that Severino throws 36% of the time, enables him to rack up the strikeouts. Severino’s strikeout rate is supported by his 74.8% contact rate and 12.2% swinging strike rate, which are both in the 83rd percentile. His outside swing rate, which measures the amount of pitches outside the strike zone that batters swing at, is not quite as impressive, but still above average. Fortunately, Severino’s fastball velocity allows him to get a lot of swings and misses in the strike zone, so he doesn’t need to rely as much on making hitters chase.
Groundballs and soft contact
While strikeouts and walks are the most important factor in determining pitcher success, a pitcher’s batted ball profile is a close second. A pitcher with an elite strikeout to walk ratio won’t be very effective if he gives up two home runs per start. In terms of batted ball allowance, a pitcher mainly controls whether the ball is hit on the ground or in the air, with groundballs vastly preferable to flyballs. To a lesser extent they control how hard the ball is it, but that’s more in the batters’ hands than theirs.
Generally speaking, high groundball pitchers are not high stirkeout pitchers. One of the main reasons is that the sinker and two-seam fastball, pitches used to induce groundballs, do not produce many swings and misses. So it’s a special combination when a pitcher can combine a high strikeout ability with an inclination for groundballs. Luis Severino is one of those pitchers. His 51.6% groundball rate is in the 84th percentile and 17th overall among MLB starters. Keeping the ball on the ground is especially important in Yankee Stadium, which increases home runs by 35% compared to the average stadium.
The other fact to consider in a pitcher’s batted ball profile is their ability to induce weak contact. Groundballs are great, but if every one is hit at 107 MPH then a pitcher will not be very successful. Conversely, even if a pitcher seldom allows flyballs, they’ll struggle if those flyballs are hit hard. Severino grades out well here too. His 29.0% hard hit rate is in the 79th percentile among starters, while his 19.6% soft hit rate is in the 57th percentile. Severino also performs well in inducing infield flyballs, which are basically as good as strikeouts, with a 68th percentile performance there.
Luis Severino, despite being only 23 years old, has pitched like one of the top 10 pitchers in baseball this season. His surface performance is supported by radar gun-popping velocity and a wide array of peripheral skills, headlined by strikeout ability, plate command, groundball inducement and a proclivity for soft contact. In essence, he’s the perfect pitcher, grading out as above average to elite in all the categories that matter in pitcher performance.