I’m comfortable to announce that we now have two pitch high quality fashions, PitchingBot and Stuff+, accessible on your perusal on the FanGraphs Leaderboards.
PitchingBot is the brainchild of Cameron Grove. We labored with Cameron to have the ability to run and keep his mannequin in-house at FanGraphs; he has since joined an MLB entrance workplace. You’ll be able to learn all about PitchingBot within the FanGraphs Library right here.
In brief, PitchingBot takes inputs comparable to pitcher handedness, batter handedness, strike zone top, rely, velocity, spin price, motion, launch level, extension, and site to find out the standard of a pitch, in addition to its doable outcomes. These outcomes are then aggregated and normalized on a 20-80 scouting scale, which is what’s displayed on the leaderboards.
There are three fashions utilized in PitchingBot: General (botOvr within the leaderboards – stuff and site), Stuff (botStf – stuff solely) and Command (botCmd – location solely). These can be found for a pitcher’s whole mixed arsenal and for every particular person pitch sort.
There’s additionally botxRV100, which is the anticipated run worth per 100 pitches, and botERA, which is that very same run worth transformed into a simple to know ERA scale.
Eno Sarris and Max Bay created Pitching+, with inspiration from work by Ethan Moore, Harry Pavlidis, and Jeremy Greenhouse, amongst others. Eno and Owen McGrattan at the moment keep and work to enhance the mannequin, with engineering assist from Matt Dennewitz. Stuff+ has been written about extensively at The Athletic. Moreover, Stuff+ and its corresponding fashions — Pitching+ and Location+ — are detailed within the FanGraphs Library right here.
Stuff+ solely seems on the bodily traits of a pitch, together with however not restricted to: launch level, velocity, vertical and horizontal motion, and spin price. Usually, the mannequin goals to seize the “nastiest” pitches in baseball. Location+ is a count- and pitch type-adjusted choose of a pitcher’s capability to place pitches in the appropriate place. It ignores a pitch’s bodily traits and appears at rely, pitch sort and site. The general mannequin, Pitching+, isn’t just a weighted common of Stuff+ and Location+ throughout a pitcher’s arsenal. Reasonably, it’s a third mannequin that makes use of the bodily traits, location, and rely of every pitch to attempt to choose the general high quality of the pitcher’s course of. Batter handedness can be included in Pitching+, capturing platoon splits on pitch actions and places.
Stuff+, Location+, and Pitching+ are all on the acquainted “+” scale (like wRC+), with 100 being common.
It’s value noting that each one pitch modeling information may be rolled as much as the group stage and can be damaged down by customized date ranges.
