In baseball, a double is the act of a batter safely reaching second base by striking the ball and getting to second before being made out, without the benefit of a fielder's misplay (see error) or another runner being put out on a fielder's choice.

Typically, a double is a well hit ball into the outfield that is able to get into the "gap" between the center fielder and one of the corner out fielders or is hit up the foul lines. To be able to get a large amount of doubles, one must have decent power and hitting skills to be able to hit it to a double area and also be able to run well enough to beat a throw by the outfielders. Doubles can typically drive in runs from third base, second base, and even from first base at times. When total bases and slugging percentages are calculated, the number two is used for the calculation. The all time leader in double hits is Tris Speaker with 793.

If a batted ball is hit fairly and bounces out of play, it is referred to as a ground-rule double. The batter is automatically given second base and any runners advance two bases from the last base that they had advanced to when the ball cleared the fence. Prior to 1931, such hits were considered as home runs.

Double leaders in Major League Baseball

Career

1. Tris Speaker - 792
2. Pete Rose - 746
3. Stan Musial - 725
4. Ty Cobb - 724
5. George Brett - 665

Season

1. Earl Webb (1931) - 67
2. George Burns (1926) - 64
3. Joe Medwick (1936) - 64
4. Hank Greenberg (1934) - 63
5. Paul Waner (1932) - 62