Ground Rule Double

A ground rule double (technically called an "automatic double" or "book rule double") occurs when a fair ball bounces and then leaves the field of play, typically bouncing over the outfield wall. The batter is automatically awarded second base.

How It Happens

Common ground rule double scenarios:

• Ball bounces in the outfield and over the wall
• Ball rolls under a fence or into the stands
• Ball gets stuck in ivy (Wrigley Field)
• Ball hits a speaker or catwalk (Tropicana Field)
• Ball bounces into the dugout

The Rules

When a ground rule double is called:

• Batter is awarded second base
• All runners advance two bases from where they were when the pitch was thrown
• The play is dead, no additional advancement

Why It's Frustrating

Ground rule doubles often cost teams runs:

• A runner on first might have scored on a ball to the wall
• Instead, they can only advance to third
• "Easy" runs become just runners in scoring position

"Ground Rule" vs. "Book Rule"

Technically, there are two types:

• Book rule double: Standard rule (ball bounces over fence)
• Ground rule double: Specific to each stadium's unique features

In practice, fans and announcers use "ground rule double" for both.

Stadium-Specific Ground Rules

Each ballpark has unique ground rules:

• Wrigley Field: Ball stuck in ivy is a double
• Minute Maid Park: Ball hitting the flagpole
• Tropicana Field: Catwalks and speakers have specific rules