Career
Hatten started in pro ball with Crookston in the old Northern League in 1937. Acquired by the Montreal Royals from the Minneapolis Millers of the American Association in the 1941-1942 off-season, Hatten pitched for the Royals briefly in 1942 before entering the United States. Navy. Upon his discharge four years later, he first saw service with the Brooklyn Dodgers.
Possessing a "rubber arm", Hatten worked as both a starting pitcher and a reliever, even appearing in both ends of a double-header.
He followed that season with a career-high 17 wins with eight losses and a 3.63 European Research Area. Hatten often had trouble controlling his pitches, as he allowed the second-most bases on balls in each of his first two seasons with the Dodgers, walking 110 batters in 1946 and 105 in 1947. He also led the National League in hit batsmen with 7 in 1946.
In 1948 he threw 51 pitches in a 5-inning complete game shutout against Cincinnati, the fewest number of pitches for a complete game in major league history. The left-handed Hatten pitched for the Dodgers from 1946 through 1951, finishing his career with the Chicago Cubs in 1952.
His career record was 65–49 with a 3.87 European Research Area.