Challenges#

Instant replay came to MLB in 2008 for home run calls and expanded to most reviewable plays in 2014. In 2026 the league added a second flavor: Automated Ball-Strike (ABS) challenges, letting batters, pitchers, and catchers contest individual ball/strike calls in real time. Both kinds can change the scoring of a play, so when they happen, you need to note them.

How MLB Replay Review Works#

There are two distinct challenge systems in today’s game.

Manager Challenges (on-field plays)#

When a manager disagrees with an umpire’s call on the field, they request a review. Play stops, the call goes to the Replay Operations Center in New York, and umpires review the video. Reviewable calls include:

• Force/tag plays at any base — safe vs out (stolen bases, force outs, tag plays at home)
• Catch / no-catch (trap) in the outfield
• Fair / foul boundary balls down the lines
• Home-run boundary calls — over the fence, off the wall, or a ground-rule double
• Hit by pitch — was the batter actually struck by the ball
• Touching a base / leaving early on a tag-up (appeal plays)
• Fan interference, stadium boundaries, collision rules at home plate, slide-interference (Chase Utley) rules

Each manager gets one challenge per game; teams keep their challenge if the call is overturned (so a team that wins challenges can keep going). Umpires can also initiate crew chief reviews on their own for certain plays.

The result is one of two outcomes:

• Overturned — the original call was wrong. The play is corrected: an out becomes a safe call (or vice versa), runners may be repositioned, a catch becomes a trap, a fair ball becomes foul.
• Upheld (or “stands” / “confirmed”) — the original call holds. The challenging team loses their challenge.

A call that “stands” means there wasn’t clear evidence to overturn it; a call that’s “confirmed” means the video clearly supported the original. For scoring purposes both mean the same thing: the original call remains.

Automated Ball-Strike (ABS) Challenges#

Starting in 2026, MLB lets batters, pitchers, and catchers challenge ball/strike calls. ABS challenges work very differently from manager challenges:

• The player must signal (helmet/cap tap) within roughly two seconds of the pitch — no delay allowed.
• Only one of three players — the batter, pitcher, or catcher — can initiate. The manager cannot.
• The challenge is resolved instantly by the computerized strike-zone system. No replay center, no delay.
• Each team gets two challenges per game; teams keep them on overturns.

An ABS overturn changes a pitch from a ball to a called strike (or vice versa). That can have downstream effects on the count and the at-bat: a 3-1 ball becomes 3-2 strike, an apparent walk on ball four becomes a still-live at-bat, an apparent strikeout becomes a still-live at-bat with a ball added.

Noting a Challenge on a Paper Scorecard#

There’s no universally standardized notation for challenges — they’re a recent addition to the game and scoring conventions vary. Use whatever works for you. A few approaches scorers use in practice:

• A small “Ch” (or “R” for Review) somewhere on the play — in the corner of the at-bat cell, near a pitch in the pitch sequence, or next to a fielding notation
• For an upheld challenge, you might mark just “Ch” since nothing actually changed
• For an overturned challenge in pencil, erase the original and write the corrected scoring (with optional “Ch” annotation)
• For an overturned challenge in ink, you could strike through the original scoring and add the corrected version, perhaps as “Ch ” — the strike-through preserves the history of what was first called

The right answer is whatever lets you read the scorecard later and understand both what happened and that a review took place. Many casual scorers don’t note challenges at all if the corrected scoring is already on the card.

In BaseballScorer#

BaseballScorer handles each challenge type with its own UI path. ABS challenges produce a visible mark in the pitch-dot sequence (circled pitch or capsule); Manager challenges produce a small “Ch” badge in the top-leading corner of the at-bat cell.

ABS (Pitch) Challenge#

After recording a pitch or play, a Pitch Challenge button appears in the review panel. Tap it to open a Challenge Result alert with three options:

• Overturned — the call is reversed. The original pitch stays visible (as a hollow dot) and the corrected pitch appears next to it.
• Upheld — the original call stands. The team loses their challenge.
• Cancel — you tapped the button by accident; nothing changes.

Visual notation in the pitch sequence: Challenges leave a distinct visual mark in the pitch dot display. Both upheld and overturned challenges are circled so you can spot them at a glance.

Upheld challenge: The original pitch dot is circled — the call was reviewed but stands unchanged. Here, a called strike was challenged and upheld:

Overturned: ball becomes strike. The original ball appears as a hollow green circle (voided), followed by the corrected called strike (filled orange dot). Both are enclosed in a capsule:

Overturned: strike becomes ball. The original called strike appears as a hollow orange circle (voided), followed by the corrected ball (filled green dot). Both are enclosed in a capsule:

The key idea: nothing is erased. The original call is always visible as a hollow circle so you can read exactly what happened — what was called, that it was challenged, and what it became. Your pitch sequence tells the full story.

Manager Challenge (play challenges)#

For on-field replay challenges — safe/out at a base, catch/trap, fair/foul, HR boundary, stolen-base reversal — open the at-bat in the review panel (tap its cell on the scorecard, or scroll back to it in the inning column). Next to the Pitch Challenge button you’ll see a Manager Challenge button. Tap it to open the Manager Challenge sheet:

The sheet has three fields:

• Outcome — Upheld or Overturned (segmented picker)
• Challenging Team — Home or Away (defaults to the batting team of the play; flip if the defense challenged)
• Note (optional) — free-form text like “trap call”, “missed tag at second”, “fair down the line”. The note appears in the inning summary alongside the play.

Tap Confirm to record the challenge.

Upheld: the challenge events are recorded against the at-bat, the challenging team’s remaining-count decrements, and you’re done. Nothing else changes — the original call stands.

Overturned: the challenge events are recorded, and you then use the existing Edit Scoring flow (or the runner-event editor) to enter the corrected scoring. For example:

Scorecard badge: an at-bat with a resolved Manager challenge shows a small “Ch” badge in the top-leading corner of the cell. (ABS challenges do not get this badge — the pitch-dot capsule / circle already conveys them.) The badge tells you a Manager challenge happened on this play; the note (in the inning summary) and the corrected scoring tell you the rest.

Challenge status bar: A persistent indicator shows how many challenges each team has remaining, broken out by pool — e.g., ABS 2/2 • Mgr 1/1. The two pools are separate in MLB 2026: each team gets 2 ABS challenges and 1 Manager challenge per game. Teams keep a challenge on an overturn (so a successful challenge doesn’t decrement the remaining count); an upheld challenge consumes it. The status bar updates automatically when a challenge is resolved.

Known limitation: real-time challenges of runner events (CS, pickoff, thrown out). A caught-stealing or pickoff call lands on the currently in-progress at-bat — the one being pitched at the time. The Manager Challenge button lives on the completed at-bat’s review panel, so there’s no entry point until that batter finishes. By then, subsequent plays (especially a home run) may have produced side-effects that don’t cleanly reconcile when the runner event is flipped after the fact. Workaround: if a real-time runner-event challenge happens during a live game, score it immediately as the corrected outcome (e.g., record the steal as safe rather than a CS), and use a play note to record that a challenge was made. The Manager Challenge button + “Ch” badge will then be missing for that play. A dedicated real-time challenge entry point is planned for a future release.

Known limitation: overturns that revert to a still-live at-bat. Some manager challenges put the at-bat back to in-progress rather than to a different final outcome — the most common is a home run overturned to a foul ball (the count goes back to where it was, the batter is still up). BaseballScorer’s Edit Scoring picker today only offers terminal at-bat outcomes, so this case has no clean in-app path. Workaround: use single-at-bat Undo to roll back the entire at-bat, then re-pitch from the corrected count. You’ll lose the “Ch” badge in this case (it’s tied to the at-bat that no longer exists), so jot a manual note in the inning if you want to record that a challenge happened. This is rare in practice — most challenges produce a different terminal outcome, not a return to a live at-bat.

Challenges are relatively rare, but they can significantly change the scoring of an inning — especially if an overturned call puts a runner on base who later scores. Recording them accurately ensures your scorecard tells the true story of what happened.

See also: Pitch Tracking | Stolen Bases