Between 1962 and 1966, Sandy Koufax put up one of the greatest five years stretches in pitching history. He won three Cy Young awards and an MVP. He was also runner up for MVP twice. He was an MVP every one of these seasons. Then…his career was over. In 1965, he started experiencing extreme discomfort in his throwing elbow, and had to resort to using pain killers every day and even in the middle of starts. In 1966, he was told his arm simply couldn’t handle pitching anymore. He played the entire season, anyway. His final game was Game Two of the 1966 World Series. After the season he would retire and in the collecting world, that was it. There would be no new cards of Koufax made. Where as Roberto Clemente played 18 seasons, and Willie Mays and Hank Aaron each played over 20, Koufax had a 12 year career, with only five being remarkable in the way we tend to remember him.
The lack of longevity in his career compared to others of his era make all of his cards more collectible. His rookie, which of course has the same continuity and wear and tear issues as other cards of the day, is incredibly desirable and can be found in only very rare instances in a high grade.
Random Sandy Koufax Fact: In 1963, Sandy Koufax threw 11 complete game shut outs on the season. Only one person ever topped this mark, Bob Gibson in 1968 with 13.