In baseball, a closing pitcher, more frequently referred to as a closer (abbreviated CL), is a relief pitcher who specializes in getting the final outs in a close game when his team is in the lead. A closer who successfully gets the final outs for their team in the final inning of a game is recorded as a save in baseball statistics. The role is often assigned to a team's best reliever. Before the 1990s, pitchers in similar roles were referred to as a fireman and stopper. Closers typically specialize in a breaking ball of some sort in order to minimize the risk of home runs late in games, and to deceive batters into swinging away from the strike zone.
In Major League Baseball (MLB), some closers have been noted for their use of entrance music when they jog out to the mound to warm up, often to excite the fans and to intimidate the at-bat. For example, the San Diego Padres of the National League (NL) played the song "Hells Bells" by AC/DC for closer Trevor Hoffman, and the New York Yankees of the American League (AL) played "Enter Sandman" by Metallica for closer Mariano Rivera.