Mariano Rivera (born November 29, 1969) is a Panamanian professional baseball player who has spent his entire Major League Baseball (MLB) career with the New York Yankees. Nicknamed "Mo", the right-handed Rivera has served as a relief pitcher for most of his career. His presence in the late innings of games to record the final outs has played an instrumental role in the Yankees' success, particularly the team's late 1990s dynasty, which won four World Series championships. Rivera was signed by the Yankees organization in 1990 and spent parts of six seasons in the minor leagues before debuting in the Major Leagues in 1995 as a starting pitcher. He found success after being converted to a relief pitcher in the bullpen. After a breakthrough year in 1996 as a setup man, he became the Yankees' closer in 1997 and has maintained that role for the team ever since. Rivera has become one of the best closers in baseball history, and he has done so by primarily throwing one pitch, a sharp-breaking, mid-90s mile per hour cut fastball that has been called an all-time great pitch. Rivera is a ten-time All-Star, a four-time American League (AL) Rolaids Relief Man Award winner, and a three-time saves leader. He has recorded the second-most saves in Major League history, and in 2009, he surpassed 500 career saves. Recognized as an exceptional postseason performer, he holds Major League postseason records for saves and earned run average (ERA), among other records. Baseball writers expect Rivera will be elected to the Baseball Hall of Fame upon retirement.