12. Mark Buehrle

When Mark Buehrle was drafted in the 38th round in 1998, nobody expected him to become the cornerstone of a championship rotation. He arrived in the majors in 2000 as a soft-tossing southpaw with a pace of play that felt like he had a dinner reservation he was running late for. By 2001, he had already surged into the upper echelon of American League starters, posting a 16-8 record and leading the league with a 1.066 WHIP. He didn't blow hitters away; he simply refused to let them get comfortable, relying on pinpoint finesse and a competitive rhythm that got batters to hit themselves out before they could even adjust their batting gloves.

The peak of his Chicago residency arrived during the historic 2005 campaign. Buehrle was the undisputed ace of the staff, earning an All-Star nod and a fifth-place Cy Young finish, but his true legacy was forged in October. During the White Sox’s first World Series title run since 1917, Buehrle etched his name into the record books as the first pitcher to start a game and then earn a save in the very next one. It was a display of selfless versatility that mirrored his entire approach to the game—whatever the team needed, Buehrle delivered with a minimum of fuss and a maximum of results.

The middle years of his journey were characterized by a staggering, metronomic consistency. From 2001 to 2011, he was the model of durability, rattling off 11 consecutive seasons of at least 10 wins and over 200 innings pitched. He became the franchise’s ultimate "big game" hunter, tossing a no-hitter in 2007 and achieving baseball immortality with a perfect game in 2009. His value wasn't just in his arm, either; he was a defensive wizard on the mound, claiming three Gold Gloves in a White Sox uniform and turning the pitcher's mound into a fifth infielder's position.

His walk toward the exit came after the 2011 season, when he departed as a free agent to join the Miami Marlins. He left the South Side with 161 wins, a championship ring, and two of the most iconic pitching performances in the city's history. While his name continues to be debated on the national Hall of Fame ballot, his status in Chicago was never in doubt. The White Sox wasted little time in honoring his decade of excellence, hoisting his number 56 to the rafters in 2017. He arrived as a long-shot prospect and left as a permanent icon, the man who proved that the fastest way to franchise immortality was to never let the hitter breathe.