Luke Gregerson has a fantastic slider.  Amongst relievers this season, his slider, which has been almost five runs above average, leads the league in effectiveness.  When starters are considered, Gregerson still ranks sixth.  Given the huge difference in innings pitched, that is incredible. Gregerson on San Diego Padres.

Of course, it doesn’t take statistics for most of us to realize Gregerson has a good slider.  That is evident by watching the games and the horrific hacks taken at the pitch by opposing hitters.

Like I did when looking at Wade LeBlanc’s change-up, I want to examine Luke Gregerson’s slider by comparing it to the sliders thrown by other top slider-throwing relievers.  I will compare Gregerson to Carlos Marmol (Chicago Cubs), Joba Chamberlain (New York Yankees), and Jonathan Broxton (Los Angeles Dodgers), all of whom have consistently ranked amongst the top righty reliever slider throwers.

First lets look at how often each pitcher throws his slider, as well as how fast it, and his fastball are thrown. Because yearly sample sizes are smaller for relievers than starters, all data is approximate, and based off multiple years of data…

Player % Slider (Aprx.) Slider Speed (Aprx.) Fastball Speed (Aprx.)
Luke Gregerson 55% 84 MPH 90 MPH
Carlos Marmol 50% 84 MPH 94 MPH
Joba Chamberlain 24% 85 MPH 94 MPH
Jonathan Broxton 23% 88 MPH 96 MPH

Gregerson throws his slider more than the other pitchers do.  This makes sense since his fastball is significantly slower than that of the others.  Not surprisingly, Broxton, who throws the hardest, also throws the least amount of sliders.  Also interesting is that Gregerson’s slider is pretty similar in speed to Marmol’s and Chamberlain’s despite his slower fastball.

Now lets examine the movement on each pitcher’s slider…

Player Horizontal Movement (Arpx.) Vertical Movement (Aprx.)
Luke Gregerson 3-5 2
Carlos Marmol 5 -1.3
Joba Chamberlain 2 0-1
Jonathan Broxton 2-3.5 1.5

This season, Gregerson has only averaged 2.8 inches of horizontal movement, compared to 5.0 inches last season.  His vertical movement has stayed consistent at approximately 2 inches.  Gregerson’s slider seems to move most similarly to Broxton’s.  Marmol’s is the outlier.  He gets serious horizontal movement, as well as some drop.  I guess there is a reason he throws his slider 50 percent of the time.

Finally, lets take a look at the pitch flight charts, which were constructed using data from each pitcher’s last five appearances…

In the birds-eye view, all of the sliders are pretty similar, except for Marmol’s.  There are however differences when examining from the first-base view.  All of the pitchers get movement on their slider–they are all top sliders after all–but they move in different ways.  And that’s sort of the take-away here.  Gregerson, Marmol, Chamberlain, and Broxton all throw their sliders a bit differently.  Yet they are all effective.

Thanks to Fangraphs and Brooks Baseball for the data, and Harry Pavlidis for the flight path tool.