In baseball, the loss of a game by the visiting team during the bottom half of the 9th inning or later. In order for this to occur, the visiting team must have a lead and lose it to the home team.
Most baseball games conclude in the 9th inning, either with the home team or the visiting team in the lead. A "walk-off" occurs when the game is tied, or the visiting team has the lead and the home team takes the lead during the 9th inning or later. The game is immediately over and the visiting team loses. The pitcher who permitted the tying of the game or who lost the lead is charged with a loss.