Mariano Rivera, closer for the New York Yankees, is probably the best closer in MLB's history. Rivera, who has spent his entire career in a Yankees uniform, holds the major league record for career saves. With all of his accomplishments, Rivera, who will be retiring at the end of the 2013 season, is certain to find himself inducted into the Baseball Hall of Fame as soon as he becomes eligible.
Jose Valverde, former closer for the Detroit Tigers, started as a replacement closer for the Arizona Diamondbacks in 2003. Two years later, he became their regular closer. In December, 2007, after five years with the Diamondbacks, Valverde was traded to the Houston Astros.
Andrew Bailey, closer for the Boston Red Sox, was first drafted by the Oakland Athletics in 2006. He spent his first three years in the minor leagues, coming up to the major leagues for the first time in 2009. His first season was an excellent one and he was rewarded with the American League Rookie of the Year award. His statistics for 2009 include 68 games played, 83.1 innings pitched, 26 saves, 1.84 ERA, and 91 strikeouts to 24 walks.
Barry Zito, starting pitcher for the San Francisco Giants, was a very strong player in high school and college. He was drafted by the Oakland Athletics in 1999 and he spent his first season and a half in the minor leagues. He was called up in 2000 and pitched in 14 games for the Athletics. The following season, his rookie year, Zito played in 35 games, pitched 214.1 innings, and had an ERA of 3.49, a 17-8 record, and 205 strikeouts to 80 walks.
Tim Lincecum, starting pitcher for the San Francisco Giants, was drafted by the Giants in 2006. He spent 2006 in the minor leagues and he was called up to the majors in 2007, playing in 24 games with the Giants. In his first season in the majors, Lincecum pitched 146.1 innings and he had an ERA of 4.00 with a 7-5 win-loss record and 150 strikeouts to 65 walks.
Zack Greinke, starting pitcher for the Los Angeles Dodgers, did not start pitching until his later high school years. In his senior year in high school, he had a 9-2 record, 0.55 ERA, and 118 strikeouts in 63 innings pitched.
Clayton Kershaw, starting pitcher for the Los Angeles Dodgers, was a star player in high school before being drafted by the Dodgers in 2006. His high school record was 13 wins to 0 losses, a 0.77 ERA, and 139 strikeouts in 64 innings pitched.
Cliff Lee, starting pitcher for the Philadelphia Phillies, was originally drafted by the Montreal Expos in 2000 but he never played with them. After two seasons in the minor leagues, the Expos traded Lee to the Cleveland Indians, who sent him to the minors for most of another season. They called him up in September to pitch in just two games and 10.1 innings. Lee again spent most of the 2003 season in the minors, playing in just nine games for the Indians that season.
Cole Hamels, starting pitcher for the Philadelphia Phillies, was drafted by the Phillies in 2002. He started his career in 2003 in the minor leagues but injuries curtailed his playing time in 2004 and 2005. In 2006, he was called up to the Phillies and he pitched in 23 games for them. Hamels statistics in his first year in the major leagues include 132.1 innings pitched, 9-8 record, 4.08 ERA, and 145 strikeouts to 48 walks.
Felix Hernandez, starting pitcher for the Seattle Mariners, was first signed by the Mariners in 2002 when he was only 16. He spent the 2003 and 2004 seasons in the minor leagues, coming up to the Mariners in 2005 at the age of 19. In his first season in the major leagues, Hernandez played in 12 games, pitched 84.1 innings, and had an ERA of 2.67 with 77 strikeouts to 23 walks.