How many innings are needed to have a complete MLB game after a rain delay?

Major League Baseball considers a regulation game to take as little as 4 1/2 innings of play before a rain delay. If the home team is leading after 4 1/2 innings and the game is called for rain, it is considered a complete game.

If either team is leading after five innings and the game is called for rain, the game is considered a complete regulation game. If the game is tied at five innings and the game is called for rain, the game is suspended to be completed at a later time. Games that have not made it to 4 1/2 innings before rain ends play are replayed in entirety at a later time.