Zone Shift
The 2026 ABS challenge system lets players overturn ball-strike calls. Did the called zone move, and what is catcher framing still worth?
Builds on Answers for Coach
- Coach questions
- 3
- Asked on air
- 10×
- Top question
- Q-16
Coach questions it could answer
The playbook →- How much is catcher receiving worth, and will ABS erase it?
Measure each catcher's framing runs before and after challenges arrived. If the best framers lose the most, ABS is erasing the skill; if the ranking holds, framing still pays on the calls nobody challenges.
- Which recent rule changes measurably changed the game?
The called-zone map before and after 2026 is a direct, pitch-level measure of one rule change, the kind of evidence the hosts asked for about every recent rule.
- What do walks cost, and what causes high walk rates?
Track walk and strikeout rates by month alongside the zone's edges. If the edges moved, walk rates should follow, which separates the zone from the pitchers as a cause.
Data it needs
The data lake →Everything it needs is on hand, so it could be built today.
The question
With challenges, a bad call can be overturned, so the zone players actually face may have changed, and the value of a catcher who steals strikes may have shrunk.
How it would work
- Map the called-strike rate by location for 2022–25 and for 2026, with the rulebook zone drawn on top, and show where the edges moved.
- Measure catcher framing before and after, per catcher, with sample sizes shown so small samples don’t look like findings.
- Show where challenges overturned calls and which way they went.
First version
- Two called-strike maps, 2022–25 and 2026, and a difference map between them.
- A framing table for catchers with enough pitches in both periods.
- Overturned calls on a zone map, from the challenges the data records.
The data
Statcast called pitches with location and each batter’s zone top and bottom. Groundwork from Answers for Coach already established two useful facts about 2026: Savant records the final call after a challenge, and the play text only logs challenges on the pitch that ended a plate appearance.
What it needs
- Working around the challenge log. Since mid-at-bat challenges aren’t logged, the analysis has to infer them or stick to what the final calls show.
- Enough 2026 games. One season of challenges is a small sample for per-catcher numbers.
Status
An idea on the launchpad. Nothing is built yet.