Luis Severino has earned his Al Wild Card game start

Luis Severino has risen to be the Yankees’ best starter. That is quite the compliment given how well their rotation performed this year. The rotation’s 4.43 RA9 ranked third in the AL, and their strikeout and walk rates ranked fourth. Now the 23-year-old Severino is the Yankees’ best hope for an ALDS appointment in Cleveland.

Coming up in the minors, scouts were excited about Severino’s high ceiling, but they also had concerns. For one, he is a bit undersized, but not by much (Baseball Reference lists him at 6’2”, 215lbs). Of much more concern is his delivery. Severino does not use his lower half effectively at all, which forces him to rely mostly on his arm strength in order to achieve his high velocities. When your upper-nineties fastball is your best pitch, such an arm-focused delivery presents substantial risk of injury, and loss of velocity could result in a big decrease in effectiveness. Furthermore, he was more or less a two-pitch pitcher, which is difficult to make work in a starter’s role. He had a great changeup, but his slider needed work.

The upshot is that Severino’s profile looked like that of a pitcher with the stuff to start, but with a delivery and repertoire that had a reasonable chance to land him in the bullpen some day. That bullpen risk made it difficult for prospect writers to rank him. He topped out at 35 in Baseball America’s rankings. Baseball Prospectus ranked him 51st in 2015. ESPN’s Keith Law never even ranked him, citing too much concern that his delivery would someday land Severino in the bullpen.

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The same team that has over-performed in seasons past is historically under-performing in 2017

Severino got off to a good start in his career in 2015. He had a 3.03 RA9 in 62 ¹⁄₃ IP with solid strikeout and walk rates. That is a 69 RA9- (yes, I calculated that myself). Then in 2016, he was catastrophic in a starter’s role. He had a 8.77 RA9 over 11 starts. He was outstanding in the bullpen, though. He had a 0.78 RA9 over 11 appearances and struck out 29 percent of batters faced. Even with the control problems he was having in relief, it looked like the bullpen was indeed going to be his destiny.

Then Severino’s slider came alive in 2017. What was once a below-average pitch has been labeled as plus by Law himself. His whiff rate was in the top ten in baseball, and of those whiffs, 43 percent of them have been off of his slider. Opposing batters hit only .182 off the pitch and slugged only .268.

In Severino’s excellent 2017 season, he had a 3.40 RA9 and struck out 29.4 percent of batters faced, while also improving his walk rate to 6.5 percent. His 3.01 DRA was even better. Severino’s 5.4 bWAR ranks 10th in the league among pitchers. He will almost certainly land in the top five of the AL Cy Young balloting, and deservedly so.

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Severino is clearly the Yankees’ best choice for AL Wild card game, and I am not sure anybody would argue otherwise. CC Sabathia also did a good job of preventing runs this year, with a 3.87 RA9, but his peripherals did not line up with that at all. He had a 4.40 DRA because he could not strike anybody out, though he was effective at inducing soft contact. Sure, Sabathia is more experienced, but better talent is always the way to go in a one-game plaoyff.

My only concern for Severino for the Wild Card game and beyond, if the Yankees advance, is that he has already pitched far beyond his previous career high in innings pitched. He is at 193 ¹⁄₃ IP. His previous career high was 161 ²⁄₃ IP in 2015 between the majors and the minors. A high innings count with his scary delivery is not a good combination. He hasn’t had any problems so far, however, and pitcher health is basically impossible to predict, so who knows.

As good as Severino is, the Yankees would be wise to limit him to two times through the order in the Wild Card game if it is a close score. It’s all hands on deck in the coin flip game, and New York’s bullpen is really, really good. They should leverage that. The bullpen’s 29 percent strikeout rate was the best in baseball, and their 3.59 RA9 was in the top three.

The Yankees are in a great position to beat the Twins at home and advance to the ALDS. But even with Severino and a stellar bullpen, variance might be too powerful of a force to overcome in just one game. Whatever happens tomorrow, it looks like the Yankees will have a strong starter at the top of their rotation for the next five years.