This baseball term refers to any additional innings following a game which is tied through the bottom of the ninth. The extra innings are played out as normal, with the visiting team playing the top of the next inning and the home team playing the bottom.
Just as in the ninth, an extra inning is considered the final inning of a game if either team maintains a lead. If the bottom of an inning ends with the visiting team leading, the game concludes with a win for the visitors. On the other hand, should the home team score a run that puts it in the lead during its half of the inning, the game ends in a "walk-off" victory for the home team.