Conversation so far:
Where did Billy Southworth go to school?
Orlando Southworth had wanted his son, Billy Southworth, to attend college. At the age of 19, he signed a contract with the Portsmouth team in the Ohio State League.
When did Billy Southworth start playing?
Billy Southworth joined the Cleveland Indians in 1913, but only appeared in one game, entering as a replacement on defense.
How long did Billy Southworth play for the Cleveland Indians in 1913?
As a player, Billy Southworth played for the Cleveland Indians in 1913 and 1915.
Did Billy Southworth play fo anyone else after Birmingham Barons in 1917?
In 1918, Billy Southworth made the Pittsburgh Pirates and played in 64 major league games.

Question: When did he start coaching instead of playing?
Self-contained rewrite: When did Billy Southworth start coaching instead of playing?