Keeping the slider down can help Severino get to the next level in 2016

The Yankees currently have six starters for five rotation spots, yet of the five, only Luis Severino did not miss time with an injury last season. The 22-year-old came up in August and made eleven mostly excellent starts, and now he’s slated to be a full-time member of the rotation in 2016. That’s exciting. The Yankees haven’t had a young MLB pitcher this promising in almost a decade.

Severino is still just a kid of course, and inevitably there will be growing pains at some point. That’s just the way it is. Hitters will adjust to him and he’ll have to adjust back, and then they’ll do it all over again, hopefully for years and years and years. Severino had a 2.89 ERA (137 ERA+) in his 62.1 innings last year, but his 1.3 HR/9 and 4.37 FIP show there is room for improvement.

“Oh, he could get better. The consistency of his pitches. The command of his fastball. And all of that will happen has he smooths out his delivery, which it seems like he has quite a bit,” said pitching coach Larry Rothschild to Brendan Kuty. Severino flew through the minors — he made 65 starts and threw 320.2 innings in the minors, which is nothing — so of course he’s going to have to work on consistency and things like that.

Severino came to the big leagues billed as a three-pitch pitcher and we saw exactly that last year. He’s got a lively fastball, a promising slider, and a changeup that fell off the table when he threw it properly. Looking over the PitchFX data, there are plenty of positives to take from last season (MLB averages in parentheses).

Almost all of that looks good. Severino throws all three pitches regularly and they all have well-above-average velocity, and they all get a lot of ground balls too. The fastball and changeup generated swings and misses at an above-average rate as well. The slider? Not so much.

The swing-and-miss rate on Severino’s slider was a real eyesore last season. It was far below the league average, which seems impossible after watching him live, but the numbers don’t lie. “His third pitch is a mid-80s slider thrown with power, which still takes a back seat to his fastball and changeup but projects as solid average when he’s finished developing,” said Baseball America (subs. req’d) in their scouting report prior to 2015.

The slider — specifically the ability to get whiffs with the slider — is something Severino could really improve going forward. Don’t take that as a knock. Severino was pretty awesome last season. Imagine how much more awesome he can be if he can start generating some more empty swings with his slider. He knows it’s something that can be improved too.

“My breaking stuff (can improve). Pounding the zone, throwing strikes. Getting down in the zone, throwing my breaking ball down in the zone,” said Severino to Kuty when asked about how he can get better going forward. Getting the ball down is always a good idea, and Severino ostensibly did a good job of that considering his overall ground ball rate (50.9%), but take a look at his slider pitch locations specifically (click for a larger view):

That’s an awful lot of sliders up and in the zone. Ideally Severino would bury the slider down and away to righties and down and in to lefties. Last summer David Laurila culled some quotes about backup sliders, which are surprisingly effectively because they’re hard to pick up and they don’t move the way the hitter expects …

… but Severino wasn’t throwing backup sliders. He was simply missing his spot, especially when you consider how many sliders were up and away to lefties. (It took me way too long to find an example of an effective backup slider. Nothing from Severino, nothing from Michael Pineda, nothing from Masahiro Tanaka, so down the line I went until I got to the now departed Adam Warren.)

Give the effectiveness of his fastball and changeup, the slider figures to be a focal point for Severino going forward, both in Spring Training and continuing into the season. The pitch has pretty good action, we saw it last year, but right now Severino elevates it a little too often, which causes problems. Once he is able to consistently locate his slider down, he’ll get more swings and misses, and it could also improve the effectiveness of his fastball. Nathan Eovaldi’s fastball played up once he emphasized the splitter. Same could happen with Severino and an improved slidepiece.

The Yankees are going to need Severino to pitch effectively this season in order to contend, even though he just turned 22 and will have to endure the usual growing pains associated with young pitchers. His workload will be monitored, stuff like that. Severino’s stuff is very good as it is, but there is an obvious way he can improve the effectiveness of his slider, and that’s by keeping it down in the zone. If he can begin to do that consistently, he’ll inch closer to his ceiling as a frontline starter.