How many runs must a team be ahead for a save situation in baseball?

A relief pitcher is eligible to earn a save if he pitches for at least an inning and his team is ahead by three runs or fewer. In some situations, the scorer can award a save to a pitcher whose team does not have the lead.

A pitcher who earns a save must be the finishing pitcher in that game and must not be the winning pitcher. His team must also win the game. The scorer can award a save to a relief pitcher who enters the game when the other team has the tying run at bat, on base or on deck. In such cases, the score at the time of entry does not matter. A save is also possible if a pitcher pitches a minimum of three innings; in such cases, the scorer may decide whether or not to award a save.