This Dutch Leonard, no relations to the first, pitched for 20 years in MLB between 1933 and 1953. He was a knuckleballer and compiled a 191-181 record over those 20 seasons. That may not sound like an overly impressive win-loss record, but the modern statistic ERA+ shows that he was at least league average, and often significantly better, every year of his career save one. He racked up a 51.7 career WAR. That included years of 6.6 and 6.3 WAR in 1947 and 1948, which saw him only compile a W-L record of 29-29 over that time. It probably didn't help that he played for the hapless Philadelphia Phillies in those years.
Hoyt Wilhelm, successor to the mantel of the most significant full time knuckleballer on Leonard's retirement, said that he learned the pitch from photographs of Dutch. Thus, Leonard's legacy continued on for another 20 years after his retirement and on into Cooperstown.
What I am listening to: American Metalhead by Sebastian Bach