| Player | bWAR/IP | bWAR | IP | From | To | Age | SO | ERA | FIP | ERA+ | BB/9 | SO/9 | SO/BB |
| Sandy Koufax | .0214 (9th) | 42.9 (8th) | 2001.1 (28th) | 1955 | 1965 | 19-29 | 2079 (3rd) | 2.93 (33rd) | 2.79 (21st) | 125 (16th) | 3.33 (127th) | 9.35 (4th) | 2.81 (12th) |
Sandy Koufax was a tough name to place. He’s probably the pitcher many people would expect to top this list. I’m surprised with how low I placed him myself.
There are a few reasons that the man known for having the left arm of God finds himself here. For one, he had arguably his best season at age thirty in 1966 which is not considered for this list. Another reason is that he pitched in one of the worst offensive environments ever. But the most important reason is that he didn’t have his first great season until he was 25-years old. He accumulated hundreds of entirely mediocre innings between his age 19 and 24-seasons that hold back many of his rate stats.
In his favor, however, once he broke through he was one of the most dominant pitchers the game has ever seen. Between 1961 and 1965, Koufax won an NL MVP award, two Cy Young Awards (which is especially notable because at this time the award was not broken up by league), and made five All-Star appearances. He also led the league in ERA four times, FIP five times, strikeouts three times, strikeouts to walks three times and, strikeouts per nine four times in a five year period.
Koufax will forever be remembered as one of the greatest pitchers ever for his outstanding run from his age-25 season through his retirement. But for the purposes of this list, discussing accomplished and not dominant, Koufax finds himself in the number six slot.