Christopher began the 1944 Philadelphia Athletics season as a member of the starting rotation along with Don Black, Lum Harris and Bobo Newsom. However, he did split time in the first half of the year between the starting rotation and the bullpen. Among those appearances was a 16-inning match against the Chicago White Sox; Christopher pitched the final four innings, losing 4–2 after Hal Trosky stole home plate. On July 14, he pitched a 4–3 victory against the Senators, helping his team defeat Hall of Fame pitcher Early Wynn for the first time in three years. After starting the season with a 4–10 record, on July 22 Christopher went on a seven-game winning streak that culminated with a 5–1 complete game victory over the White Sox. He finished the season with a 14–14 record, 84 strikeouts and an ERA of 2.97. After the season ended, Christopher and others went on a barnstorming tour throughout the United States, ending in Wenatchee, Washington.