Age 45: Jamie Moyer (2008)
The list would not be complete without including the ageless wonder Jamie Moyer, who started his career as a 23-year old with the Cubs in 1986. Struggling to get out big league hitters consistently over his first five seasons with the Cubs, Rangers and Cardinals, Moyer had a 32-54 record. After signing with the Tigers and then released without appearing in a major league game, Moyer appeared to be done at the age of 29.
The Orioles gave Moyer a shot in 1993 and he delivered with 12 wins and an ERA of 3.43. After a brief time in Boston in 1996, Moyer was traded to Seattle where he enjoyed most of his success. He won double-digits games eight consecutive seasons, twice over 20 with an All-Star appearance in 2003 at the age of 40.
The Phillies traded for Moyer in exchange for Andy Baldwin and Andrew Barb on August 19, 2006. After winning five the rest of the season with the Phillies, Moyer posted 14 wins in 2007 despited a high ERA of 5.01.
Moyer was a key contributor in 2008 at the age of 45, helping the Phillies second World Series title. He won 16 against just seven losses with a decent ERA of 3.71, logging 196 1/3 innings. Moyer won 22 more games with the Phillies over the next two seasons.
After a devastating injury, Moyer was out of baseball in 2011 but made it back to the show with the Rockies in 2012, become the oldest pitcher to earn a victory at the age of 49. Moyer retired with 269 wins and 2441 strikeouts in 4074 innings.