Starting pitchers are the most important variable to consider when handicapping a baseball game. Even the best teams will find themselves listed as underdogs if their fourth or fifth starter has to line up against their opponent’s ace. That’s good news for bettors who can accurately evaluate pitchers and their effectiveness. But what happens when you do all the work on the game’s starting pitchers, only for one of them to get scratched after you place the bet? The short answer: it depends, both on which book you bet with and what market you wagered on. For the longer answer, let’s dive into what happens in MLB betting when the starting pitcher gets scratched or otherwise changes.

MLB Betting: What Happens if the Starting Pitcher Changes or is Scratched?
The effect of a pitcher change on your MLB bets is often something you determine — whether or not you realize it. Most sportsbooks give you a few different options to choose from when you are getting action on MLB moneylines. You’ll get to choose between “action” and “listed pitcher.”
“Action,” the default option, means that your bet is locked in regardless of the pitching change. Let’s say you bet on the Los Angeles Angels at -170 over the New York Yankees, with Shohei Ohtani on the hill for Los Angeles and Domingo German for the Yankees. Then, thirty minutes before game time, Ohtani comes down with a cold and is scratched, moving the moneyline to -110 for both sides. If you entered your bet as action, you’re out of luck. The bet stands, and despite the Angels no longer having as much of an advantage, you will have to eat the -170.
Here’s an example from FanDuel Sportsbook. If you haven’t registered at FanDuel, you can check out their special sign-up offers here!

Note “action” in the betslip. That option is on by default. If you don’t want the risk of one of the starting pitchers getting scratched, you will have to make the change. Clicking action brings up a dropdown menu with several alternative options.

As you can see, you have the option to select action, either one of the team’s starting pitchers or both starting pitchers. In the scenario your chosen starting pitcher gets scratched, so will the wager. FanDuel will void the bet, and you’ll receive the stake you wagered.
So is there a strategy behind whether you should choose action, a single listed pitcher or both listed pitchers? Let’s say you wanted to buy the San Francisco Giants because you trust Logan Webb against the Los Angeles Dodgers. If you choose only Webb, your bet will be action no matter who the Dodgers start — even if they pivot to a better pitcher like Clayton Kershaw. If that happens, you would’ve been able to buy Webb and Giants for a much better price after the move than before it.
That said, those scenarios are rare. You are generally likelier to benefit from the opposing team scratching their starter, so doing so is often strategic — just not when the team you’re fading is well-rested and at the tail end of its rotation.
Note that listed pitcher and action are almost exclusively options for the moneyline. If you decided to fade the Dodgers’ bats because Webb is scheduled to take the mound, any player prop bets you placed won’t void if he gets scratched.