In baseball, a ground rule double is an award of two bases from the time of pitch to all baserunners including the batter-runner as a result of the ball leaving play after being hit fairly and leaving the field under a condition of the ground rules in effect at the field where the game is being played. An automatic double is the term used to refer to a fairly hit ball leaving the field in circumstances that do not merit a home run as described in Major League Baseball (MLB) rules 6.09(e) through 6.09(h). The automatic double (or rule-book double) is quite often mistakenly called a ground rule double.