Pittsburgh Pirates: The Characteristics Of The Slider

(Photo by Dilip Vishwanat/Getty Images)
(Photo by Dilip Vishwanat/Getty Images) /

The Pittsburgh Pirates have two pitchers with the makings of plus sliders in Kyle Crick and Nick Burdi.  How do their pitches play this well?

In Neal Huntington’s meeting with the media on Sunday morning, a question about relief pitcher Kyle Crick’s spin rate came up:

"“If you can put on your pitching coach hat for a minute, Crick’s slider spin as you is like elite.  What have you known about him over the years about this slider.”"

The Pirates general manage gave a response, mentioning that the spin rate (rotations per minute) is part of the puzzle, but certainly not the only piece:

"“Our scouts did a really nice job of identifying the mid upper 90s velocity that he’s shown in the past.  The power of the breaking ball, our analysts did a nice job of identifying the spin rates and recognizing that’s a guy that when he throws strikes… but man that’s a wipe out pitch right-on-right and he’s got such action with it it gives left-handers a tough time as well."

The follow up was a question regarding when Huntington talks with his analysts and the importance of the actual spin rate, with Huntington’s response,

"“It’s all important.  It’s one thing to have a dominant spin rate, it’s another thing to not be able to land it for a strike or to have it have a trackable path, so there’s also deception in it.  It is an important part of the process but it’s not the only component as we evaluate a pitch”"

Both because Kyle Crick was used as the example and because his slider approach (25 percent) in terms of breaking balls, let’s use him and his 2018 as example one for what Huntington is illustrating.

Looking at basic pitch data from the trackman radar system via baseball savant, produces the following summary data regarding Crick’s repertoire:

The first thing that jumps off the page is Crick’s spin rate,

which ranked the highest in baseball among pitchers with 100 or more sliders

, and

while his fastball is his bread and butter

, 43 percent of his strikeouts came via the slider and he got a whiff on 43.64 percent of swings against the pitch.

Looking at the movement of each pitch


The slider has good movement glove side, and after the Andrew McCutchen trade last offseason, Kiley McDaniel of Fangraphs wrote about Crick,

"“He works 94-97, touching 98 mph, and his slider is above average to plus, but his heater is straight and he has trouble throwing the slider for a strike. “"

This relates to what Huntington mentioned; Crick was able to find the zone and throw the slider as a strike while also being able to induce swings and misses because of the movement.  Looking at the movement of the pitches statically provides some insight, but Huntington talked about “the path” and using the pitchRx package in R, a visual look at the pitches can be seen:

Since that’s all of the pitches overlapping, it can be hard to see, therefore taking the average of each pitch type gives a better view of the pitches:

Crick’s slider (purple) follows suit of the fastball (green) that he throws, it just trails because of the near 14 mile per hour difference, but it’s a similar path taken as the fastball.  This allows Crick to play the two off each other and allow the pitch to get swings and misses.  One other static look demonstrates this as well:

The green is the changeup, orange the two-seam, yellow the four-seam, and white the slider.  On average, the slider and four seam come out of the hand similarly and at about 15 feet away from home plate, the slider separates from the four-seam and moves off the plate.  So while the slider does have elite spin rate, that path plays an advantage for Crick and allows the slider to be a plus pitch.

Another example why spin rate isn’t the only thing that matters comes in the fact the Pirates traded away Tyler Glasnow, who ranked fourth in slider spin rate among pitchers with at least 100 sliders in 2018.  But Nick Burdi might be a better example, as his spin rate entering games Monday was 2448 rpms, which in 2018 would rank below Aroldis Chapman (ranked 114) and just ahead of Jordan Hicks (ranked 136).

Burdi’s slider has been considered plus by scouts, Fangraphs gave him a 60 future on the slider, a year after giving a 70 on the pitch (presumably the Tommy John being a factor).  MLB Pipeline gave the slider a 65, so the pitch is clearly above average to plus despite the “meh” spin.  And it’s the other characteristics as to why, ie “the path.”  Using data from Brooks Baseball, here’s how Burdi’s pitches looked on both opening day and yesterday, April 8th.

On opening day, here are how Burdi’s pitches looked:

Looking statically at the pitch path where red is the fastball and blue is the slider:

Burdi’s slider follows similar movement as the fastball, but on opening day the pitch diverged from the path of the four-seam at around 50 feet from home, but we’re dealing with a small sample of five fastballs and nine sliders, though he did pick up four swinging  strikes on the pitch.  Looking at his last outing against the Cubs, Burdi’s pitches moved much more in sequence:

The right-hander didn’t throw a slider to the left-handed batting Victor Caratini, instead throwing his upper 90s fastball.  Again, looking at a static image of the average movement of each pitch gives a look at the path:

Burdi’s slider yesterday followed the fastball more closely, starting to diverge from the fastball more around 25-30 feet.  His slider, despite the non elite spin rate, has been an excellent pitch for the 26-year-old so far in the early part of April because of the way it comes in and dives glove side out of the zone, along with the velocity in which the pitch is thrown.

Next. Polanco, Diaz Begin Rehab Stints. dark

Crick’s slider plays because of not only the elite spin rate, but because of how closely he can mirror the path that his four-seam fastball has, and with his velocity, Crick was able to be an effective reliever in 2018.  Burdi looks to go in the same route, having an upper 90s fastball with a slider that follows a similar path and a slider that sits in the upper 80s.  Hopefully Burdi can capitalize on his fast start, striking out eight of his first 16 batters, and stay healthy in 2019 and Crick can return healthy and pitch like he did in 2018.  Both pitchers have the makings of plus pitches in the slider.

*Numbers from Baseball Savant and Brooks Baseball