Andrew Miller is not getting strikes with his slider

This spring, I was able to make my first-ever trip to Cardinals Spring Training. It was a Friday night and I was sitting alongside the Cardinals bullpen, with a beer in my hand, wearing shorts in March. It was a good night.

Around the 5th inning, Andrew Miller started getting loose. I even shot a little video.

Miller entered the game in the 6th, with one out and a runner on 1st. He walked the first three batters he faced on twelve straight balls. As I recall, every single one of them was a slider that wound up about a foot into the right handed batter’s box. Probably, he set out to work on his slider that day, so I get it. But 12 straight sliders that miss the strike zone by about a foot is not ideal... especially a week before the season starts.

We’ve now seen Miller make two appearances in actual games and that slider is still a problem. So of course, it’s just spring training and two appearances and yada-yada-yada. But that wipeout slider is Andrew Miller’s primary weapon, and its diminished effectiveness traces all the way back to the beginning of 2018.

Miller became a full-time reliever in 2012, but it was in 2015 that he solidified the repertoire that has defined him, throwing just a slider and a fastball, with heavy reliance on the slider. Every year since 2015, he has thrown between 55 and 60 percent sliders.

Not only are the majority of the pitches Miller throws sliders, he predominantly dumps them into the same zone: Low and away to a lefty, low and inside to a righty, off the plate. (From now on, I’ll mostly refer to Miller as if he’s facing a lefty, but he throws an almost identical mix to the same zones for righties as well).

Here’s a look at where he’s thrown his slider since he became a full-time reliever:

That’s a tremendous percentage of his pitches which are going low-and-away to a left hander, and especially into that box that is both low and outside. You can only do that if you’re getting hitters to chase those pitches consistently. And from 2015 through 2017, that’s exactly what he was doing.

In the three most dominant seasons of his career, Miller was getting hitters to swing more than half the time at pitches that were low, outside, or both. There are only two outcomes for a hitter swinging at those pitches: Miss or make terrible contact.

The risk for a pitcher who is peppering those zones with pitches is that they are balls. If hitters stop swinging at them, they will be allowed to walk to first base, as per the rules of baseball.

Here’s the swing percentage on Miller’s sliders since the start of 2018:

Just look at that low-and-outside corner and you can see a pretty substantial difference. Hitters used to swing at that pitch more than half the time. Now, they’re only swinging about a third of the time. If you’re in a race to accumulate three strikes before the batter gets to four balls, the odds are not in your favor.

Miller was never aiming to “hit the corner” with his slider. He was aiming to miss the corner, but due to the hellish break on the pitch, convince the batter otherwise. Here’s where his sliders were going in 2016:

The highest concentration of pitches is out of the zone, but just a bit out of the zone. We’re obviously very early into 2019, but it looks like just as I saw in that Spring Training game, Miller’s slider is sliding TOO FAR off the edge of the plate.

So is Miller missing by more with his slider, or are batters just not swinging at it as much? My guess is both. Miller’s slider is nasty enough to get batters to chase, but there’s a limit to how far they’re going to go. Thus far in 2019, both in spring and the young season, Miller has not been able to hit that point just outside the zone where hitters can’t let it go.

And once word gets out that Miller can’t hit that spot, there’s no reason to swing at the slider at all. Let him work himself into a hitter’s count, then sit on the fastball.

If there’s any good news, it’s that Miller’s velocity on both his pitches is up a tick from last season, when he was battling injuries, and remains more-or-less where it was during his peak years. So maybe his command will come around.

At the risk of sounding like a sports radio guy, I’m “on record” as being skeptical of any free agent deals for relievers... and this is a good example of why. I’m not saying Andrew Miller is a bust or anything like that. We’re only looking at a very small sample size of early season results. He may well turn it around, and I hope he does.

But what this illustrates is just how thin the margins are for relief pitchers - even recently elite ones. With a guy like Miller - who only throws two pitches - if you suddenly lose your feel for one of those pitches... what have you got left?