In baseball, a closing pitcher, more frequently referred to as a closer, is a relief pitcher who specializes in getting the final outs in a close game when his team is leading. The role is often assigned to a team's best reliever. Before the 1990s, pitchers in similar roles were referred to as a fireman, short reliever, and stopper. A small number of closers have won the Cy Young Award. Eight closers have been inducted into the Baseball Hall of Fame: Dennis Eckersley, Rollie Fingers, Goose Gossage, Trevor Hoffman, Mariano Rivera, Lee Smith, Bruce Sutter and Hoyt Wilhelm.
Former Yankees closer Mariano Rivera, one of the most prominent closers in baseball history, has the most career saves of any MLB pitcher (652).
Bruce Sutter was the first pitcher to start the ninth inning in 20 percent of his career appearances.
Lee Smith in 1994 was the first pitcher to start the ninth inning in over 75 percent of his appearances.
By relegating Dennis Eckersley to mostly one-inning save situations, manager Tony La Russa (pictured) was instrumental in the development of the modern closer.
In baseball and softball, a relief pitcher or reliever is a pitcher who pitches in the game after the starting pitcher has been removed because of fatigue, ineffectiveness, injury, or ejection, or for other strategic reasons, such as inclement weather delays or pinch hitter substitutions. Relief pitchers are further divided informally into various roles, such as closers, setup men, middle relief pitchers, left/right-handed specialists, and long relievers. Whereas starting pitchers usually throw so many pitches in a single game that they must rest several days before pitching in another, relief pitchers are expected to be more flexible and typically pitch in more games with a shorter time period between pitching appearances but with fewer innings pitched per appearance. A team's staff of relievers is normally referred to metonymically as a team's bullpen, which refers to the area where the relievers sit during games, and where they warm-up prior to entering the game.
Cleveland Guardians relief pitchers Aaron Fultz and Rafael Betancourt warming up in the bullpen at Jacobs Field in 2007
The bullpen car used by the Boston Red Sox to cart relievers into games