Early-Season Pitch-Modeling Standouts

This offseason, FanGraphs got some new stuff. More precisely, we got some new ways of measuring stuff, and command, and pitching overall, via pitch-level modeling. You can read about PitchingBot here and Stuff+ here. They’re really cool! Pitch modeling is a wonderful tool to both verify the eye test – that nasty-looking slider you saw, it’s actually nasty – and to find new pitchers to keep an eye on. Sure, strikeout rate and ERA and FIP can do that too, but stuff is a purer signal, because it’s entirely in a pitcher’s control. There’s no question of whether a hitter spoiled a great pitch, or whether that ball should have been a home run. There’s only the pitch, with its movement and velocity and release point.
Eno Sarris, the proprietor of Stuff+, has written about how quickly that model stabilizes, but for our purposes, let’s just say this: these pitch modeling tools give a great early look at which pitchers are working with the best tools early in the year. That doesn’t mean that they’ll all be great – they might not wield the tools in the correct order, or they might struggle with command, or they might wear down as the season goes on – but it does mean that they’re starting with an advantage.
I’d caution you against using these with excessive granularity this early in the season. If a pitcher’s Stuff+ has declined from 119 to 116, or if your team’s swingman has vaulted two points above the fifth starter, there’s probably not much signal in that. Instead, I’m going to paint with a very broad brush. I’m going to look at three groups of two today: two pitchers who both models agree have great stuff, two pitchers who both models are down on, and two where the systems disagree.
Let’s start with the good stuff. Read the rest of this entry »









