St. Louis Cardinals: What’s so special about Miller’s slider anyways?

MILWAUKEE, WISCONSIN - MARCH 31: Andrew Miller #21 of the St. Louis Cardinals throws a pitch during the seventh inning of a game against the Milwaukee Brewers at Miller Park on March 31, 2019 in Milwaukee, Wisconsin. (Photo by Stacy Revere/Getty Images)
MILWAUKEE, WISCONSIN - MARCH 31: Andrew Miller #21 of the St. Louis Cardinals throws a pitch during the seventh inning of a game against the Milwaukee Brewers at Miller Park on March 31, 2019 in Milwaukee, Wisconsin. (Photo by Stacy Revere/Getty Images) /

Andrew Miller has rebounded mightily since the All-Star Break after a sub-par first half with the St. Louis Cardinals. How has he been doing it?

The bullpen for the St. Louis Cardinals have been one of the team’s only consistent strengths this year. While some pitchers have gone cold at times, overall it has been overwhelmingly great. Especially in the second half of the season, Andrew Miller has been no exception.

I took it upon myself to analyze one of the most iconic pitches in baseball. The 37-year-old Miller has baffled the league’s most feared hitters not only in the regular season but also on baseball’s biggest stage, the World Series. But what makes this pitch so exceptional?

When analyzing a pitch, such as Andrew Miller’s slider, a few bases need to be covered (pun intended). Pitch grip, pitch break, and tunneling are a few topics I’ll be covering in this in-depth breakdown.

Pitching Repertoire

To understand what makes Andrew Miller’s slider so effective, it’s important to understand what all is in his pitching repertoire. To compliment that devastating wipeout slider, Miller also offers a mid to low 90’s four-seam fastball, a change-up, and a sinker. According to Brooks Baseball (from which I’ll be extracting most statistics in this article), Miller throws either his fastball or his slider 80% of the time.

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His fastball averages around 93- 94 mph with some sinking depth and decent arm-side movement. Although his four-seam fastball doesn’t have an excessive amount of run, he’s able to throw this pitch off the slider which generates an above-average whiff%.

The change-up, which only accounts for 5% of his pitches thrown, doesn’t offer much in terms of horizontal movement in reference to his fastball, but it is about 10 mph slower and is most likely used to disrupt a hitter’s timing.

His sinker, which is used just as scarcely as his change-up, runs the most arm-side as one can expect from a sinker and, because it is as fast as his four-seamer, he can use this pitch to jam LHH.

As you delve into Miller’s pitch usage in specific counts against both RHH and LHH, Miller has relied heavily on his fastball when behind in counts. The opposite is true, however, when Miller was ahead of hitters throwing his slider at a higher clip to generate the swing and miss for the strikeout.

Whiff Percentage

Speaking of swing and misses, LHH found that pitch so difficult to make contact with that in any count, Miller’s whiff rate was a staggering 20% against that slider. That number jumps to 26% when Miller threw it in any count with two strikes.

What’s even more amazing is when he throws his slider down and away outside of the zone to an LHH, the whiff% is an astronomical 80% (146/184)!

In comparison, (and I know I’m comparing a starter to a reliever) Chris Sale, who is also a left-handed pitcher that has similar pitch usage rates against LHH, generates an 18% whiff rate in any count and a near 20% whiff rate in any two-strike count versus an LHH. Granted Sale faces more hitters but this comparison puts into perspective just how enormous Miller’s whiff percentages actually are.


Andrew Miller hasn’t given a ton of information regarding the supposed “secret” to throw his physics-defying pitch. In fact, in a 2016 interview as a member of the Cleveland Indians, Miller claims there is no secret to throwing his trademark pitch.

In the aforementioned interview, he reveals he grips the ball over two seams as if he was throwing a two-seam fastball, but instead of his index and middle finger laying on top going along the seams, he holds the ball across the seams with his thumb tucked underneath almost directly beneath his index finger.

As the ball is coming to his release point, it’s as if he shows the hitter the side of the baseball and then finishes by turning his wrist over. This grip coupled with his three-quarter arm slot and his wrist action gives him that desired sideways tilt that tails away from a left-handed hitter. This video from Rob Friedman best exemplifies the delivery and grip of Miller’s slider.

Although I referenced Miller’s arm slot vaguely as “three-quarters”, there are actually measurements that can give even more insight to how he whips this pitch across the zone. Early in his career, Miller was a starter and opted to throw a bit more over the top with most of his pitches clumped at similar vertical release points.

During the 2009 campaign, all of his pitches hovered at the 6.6-6.7 ft range. Between 2010 and 2012, a downward trend in Miller’s vertical release point of his pitches dropped as low as 5.37 ft in 2012. More interestingly, his slider release point veered from his other pitches as he became a full-time reliever in 2012.

As of recently, the release point of his slider is the lowest it has been around the 5.32-5.44 ft with his fastball in the 5.72-5.86. That’s a ton of numbers, but it’s interesting right! Now let’s discuss pitch tunneling and how Miller can use his mechanics to ensure the batter doesn’t know what’s coming.


Pitch tunneling has become an intriguing topic when discussing a pitcher’s offerings to a hitter. The goal of a pitcher is to have his delivery so repeatable and routine that he can snap off different pitches from the same release point in order to mask his distinct pitch movements. An example would be this two-pitch sequence from Miller back in September of 2018.

Some of the best pitch tunnelers in the game include Jon Lester of the Chicago Cubs and longtime San Francisco Giant, Madison Bumgarner. Based on the stats above, Miller has slightly different vertical release points for his pitches whereas Jon Lester is almost surgical with his release points. Among all five of his pitches, Lester maintains very similar horizontal and vertical release points.

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Although Miller may not be the best tunneler, he remains extremely effective with his slider/fastball mix. Many fans were scared the old Miller would never return after his first-half performance. While he may never be quite that dominant again, he is nonetheless an integral part of the team’s bullpen.