Most everyone knows about the achievements of the dominant, young pitchers.
For instance, in just his third year in his professional career, Roger Clemens won not only the A.L. Cy Young Award in 1986, but the A.L MVP Award as well.
Tim Linececum's achievements as the 2008 N.L Cy Young as a 22 year old are also well documented. When Dwight Gooden was a mere 20 years old, he posted what I consider the most dominant season of any modern day pitcher.
Everyone wants to see youth and flash, but what about when a pitcher loses 10 mph on his fastball? The pitchers who thrive off guile and finesse are ones I believe are far greater than the Sandy Koufax's of the world who pitch six great seasons.
Continued success is key to baseball, and these are the pitchers who continued their success late into their careers.