Listed Pitcher vs. Action
Starting pitchers have a large impact on the outcome of baseball games. Due to this, the odds set by sportsbooks are adjusted based on the starting pitcher. If the starting pitcher changes for a game sportsbooks may make adjustments to the available odds and even existing bets. When placing bets on MLB games, you may see the terms "Listed Pitcher" or "Action".
MLB games have the expected starting pitchers listed ahead of time. This is called a “Listed Pitcher.” You sometimes have the choice of making the listed pitchers a condition of your money line bet. If any of your bet’s listed pitchers do not start the game, your bet will be voided. Listed Pitchers can apply to other bets. Different sportsbooks have different tendencies.
Placing an “Action” bet means that your bet will stand no matter which pitcher starts the game. Some sportsbooks might change the odds of your bet if there is a change from the originally listed pitcher. This is unlike other sports, where the odds are locked in at the time of placing your bet. Some sportsbooks will display the name of the pitcher even on action bets. Know your house rules.
See below for some example screenshots on how to select listed pitchers vs action on Money Line bets. To be able to select the listed pitcher, you must click on the individual event. Do not bet from the main screen even though there are names listed for the pitcher.
Impact on Matched Betting
If your matched bets are not placed with ‘both listed pitchers must start’ then you run the risk of losing money, since one bet could be voided or have its odds changed.
You should make sure that both bets you place will be graded in the same fashion on both books. To do this, you need to understand the house rules. For example, as of this writing, FanDuel states the following for action:
Action: All Money Line wagers are defaulted to "Action" meaning all wagers struck will NOT be voided if a pitcher change occurs. Wagers will be honored at the odds at bet placement and settled as normal.
FanDuel has elected to not move the odds if the pitcher(s) change on your money line bets. However, if you hedged an action bet on FD with a listed pitcher bet on MGM you will face risk. If one or both of the pitchers change, the FD bet will stand but the MGM bet will void. This means you no longer have all outcomes covered and are at risk of losing money.