A routine exercise in baseball in which infielders throw the ball to one another after recording an out. Players only throw the ball around in this fashion when there are no men on base.
The practice of throwing the ball “around the horn” is traditional and serves no real in-game purpose other than to keep the arms of infielders loose as an inning progresses. There are two typical scenarios in which the ball is thrown around the horn: (1) after an out is made at first base, the first baseman will throw the ball to the second baseman, who throws the ball to the shortstop, who throws the ball to the third baseman, who then returns to the ball to the pitcher. (2) After a strikeout, the catcher throws the ball to the third baseman, who throws the ball to the second baseman, who throws the ball to the shortstop, who then returns the ball to the pitcher. The order and infielder positions involved in throwing the ball around the horn can vary from team to team.
5-4-3 and 6-4-3 double plays are sometimes referred to as “around the horn” plays as the progression of throws between players is similar to this practice.