Pitch run value: grading every single pitch
Can you put a number on one slider, low and away, fouled off? Yes — with Level 3's price list.
Every count has a run expectancy — 3-1 favors the hitter, 0-2 the pitcher. Every pitch moves the count (or ends the plate appearance), so every pitch shifts expected runs by some amount. Credit that shift to the pitch and you have pitch-level run value.
Why this is the endgame of the linear-weights idea
Sum over a season and you can say 'his sweeper was worth −18 runs to opponents' (negative = good for pitchers). It's how Savant grades arsenals, how teams decide which pitch to shelve, and it's just the Level 3 accounting applied at the finest grain the game has.
Reader beware: run value bundles usage, sequencing, command, and defense-independent luck into one number. A pitch can grade great because it's thrown rarely and only in perfect spots. Check per-100-pitch rates and usage together.
How this stat lies to you
- Great value on low usage often just means good sequencing — throw it 40% and watch it get normal.
- Balls in play drag defense/luck back into the number (it's not FIP-clean).
- Year-to-year pitch values are noisy; movement and whiff profiles are steadier.
Check yourself
1. A pitch's run value comes from…
2. A changeup thrown 6% of the time grades at −3 runs per 100. Safe conclusion?