From BR Bullpen
Closers, like many other relief pitching roles, are a relatively new addition to baseball. ESPN.com points to Bruce Sutter in 1979 as the game's first closer, as he was called upon only when his team was in the lead. Later, in 1988, Oakland Athletics manager Tony La Russa further defined the closer role by using pitcher Dennis Eckersley only in the 9th inning when the A's had the lead. This is how closers are commonly used today, typified by New York Yankees pitcher Mariano Rivera, arguably the best closer in MLB history.