Stoefen, partnering with compatriot
George Lott, won three Grand Slam doubles titles:
1934 Wimbledon Championships,
1933 and
1934 U.S. National Championships. In 1933 he was ranked world No. 9 by Pierre Gillou (president of the
Fédération Française de Tennis) and World No. 10 by
A. Wallis Myers of
The Daily Telegraph. Stoefen reached the semifinals of the U. S. Championships singles in 1933, losing to
Fred Perry in straight sets. In 1934 he played for the US
Davis Cup team and won all his six matches, including the only match the US won in their defeat in the final against Great Britain. Also in 1934 Stoefen won the
U.S. Indoor Tennis Championships singles event, defeating
Gregory Mangin in the final in three straight sets. Stoefen signed a professional contract in November 1934 with promoter Bill O'Brien. In January 1935, at Madison Square Garden, he started a series of head-to-head matches against
Ellsworth Vines and by March trailed him 1–25. ==Personal life==