Void / No Action
A bet is voided (also called “no action”) when the conditions required for it to settle don’t occur. The book cancels the bet and refunds the stake — like the bet was never placed.
When Bets Are Voided
Common scenarios:
Game postponements or cancellations. A weather-postponed MLB game might void all single-game bets if it isn’t rescheduled within 24-72 hours. The exact rules vary by book and sport.
Player props if the player doesn’t participate. If you bet “Patrick Mahomes Over 250.5 passing yards” and Mahomes is a healthy scratch (or doesn’t take a snap due to early injury), the prop typically voids. Books vary on the threshold — some require zero participation, others require under a minimum number of plays.
Game cuts short. A baseball game called early due to weather may void totals and run-line bets, depending on the book’s rules and how many innings were played. Some books settle bets after 5 innings (a complete game by MLB rules); others require the full 9.
Pitcher changes in MLB. “Listed pitcher” bets (where the bet is contingent on specific pitchers starting) void if either listed starter doesn’t pitch. Action-bets (no pitcher listed) settle regardless.
Significant rule violations. Disqualifications, refusals to play, and similar irregularities can void bets at the book’s discretion.
Books occasionally void on their own errors. When a book posts a clearly-wrong line (e.g., a player listed as +5000 to score 1+ point in a game they’re definitely playing), they reserve the right to void bets placed at the obviously-erroneous price.
Why It Matters
Voids matter most for arbitrage bettors:
A voided leg breaks an arb. If you’ve placed both legs of an arb and one gets voided, you’re left exposed to the unhedged side. This is one of the main execution risks in arbitrage betting.
Books vary in their void rules. Some books are more aggressive about voiding bets they find inconvenient. This is one of the reasons bettors keep notes on which books are reliable for arbitrage purposes — book reliability matters, not just price.
Player prop voids are particularly common. Pre-game injury news, scratches, and DNP decisions void player props all the time. For prop arbitrage, this is a meaningful operational risk.
How Bettors Manage Void Risk
Watch the news. Late injury reports, weather updates, and pitcher changes affect whether bets are likely to void.
Avoid placing the second leg of an arb if news has changed. If you’ve placed Leg A and then news breaks that might affect Leg B, you may be better off skipping Leg B and accepting the unhedged exposure rather than placing into a likely void.
Know your books’ void policies. Major books publish their settlement rules. Sharp arbitrage bettors keep notes on book-specific quirks (e.g., which books void player props after 0 minutes vs after 1 minute of play).
Diversify across books. A single voided arb is annoying. A pattern of voids at the same book is a problem. If one book consistently voids your bets at high rates, consider whether to keep using them.
For more on the operational risks of arbitrage, see Arbitrage Betting Explained.