Allen was traded from the Dodgers after the 1971 season, and the ChiSox were rewarded immediately as he won the 1972 American League MVP. That season, he would finish first in Home Runs (37), Runs Batted In (113), Walks (99), On Base Percentage (.420), Slugging Percentage (.603), OPS (1.023), and he batted .308. The First Baseman was an All-Star that year and would be again in 1973 and 1974. In the latter season, he won his second Home Run Title (32) and would also finish first in Slugging (.563) and OPS (.938).Chicago traded him to Atlanta (who later traded him back to Philadelphia), and Allen's play declined rapidly. In the three seasons, he was with the White Sox, and he had 85 Home Runs with a Slash Line of .307/.398/.589.