The Baseball Hall of Fame has this to say about Alexander, who career wasn't all together happy: "Suffering from epilepsy, haunted by his experiences in combat during World War I and shadowed by the dark side of alcoholism, Grover Cleveland Alexander was able to win 373 games during a 20-year major league career, the third highest total in major league history. He led the league in ERA on four occasions, wins in six different seasons, complete games six times and shutouts during seven campaigns. Alexander also won 30 or more games three consecutive seasons."
Curiously, Alexander's life was the subject of a biopic in 1952, a couple of years after he died. Ronald Reagan played Grover Cleveland Alexander.