Parker Messick had his 2nd worst command day of the year yesterday. He dropped from 80th to 12th percentile command, walking 4 batters in 2.1 innings.

The problem is that command's influence is observable *conditional* on stuff. (Raw command is uncorrelated to ERA) It's a huge survivorship bias (good stuff guys get away with bad command) - there's a negative correlation between stuff and command. 2/3

3 things are true at the same time: - Command is worth 1/3 Stuff - Command stabilizes almost as fast as Stuff - Adding Command on top of Stuff doesn't dramatically improve ERA prediction Why? 🧵 1/3

As @pitchprofiler & others mentioned, maybe there's some "minimum command" to be a viable pitcher (throw enough strikes). I managed to find *some* hockey stick going on but it looks like it's driven by K% dropping (not BB% going up disproportionately). It's hard to show in MLB because these pitchers already proved they could throw strikes in the minors!

For reference, going from worst stuff in the league to best is worth 3 ERA. So, stuff is arguably 3x as important as command (at the MLB level)!

Fastballs are almost twice as command dependent as Breaking balls. Anyone have an idea why?

Going from worst command in the league to best is worth 1 ERA! There's a strong correlation between xERA (unexplained by Stuff+) and command. And it gets really interesting because some pitch types are way more dependent on command than others (see below)

Justin Martinez dotted SIX out of 9 pitches during his immaculate inning!

Thanks for reading. In the future I'll be focusing on analyzing pitcher-batter matchups!

Let's be liberal and assume it's 2 big jumps away from ground truth: a true mean miss of 10.5in. This means OpenCommand's target estimate is 3.72in away from true target *on average*!