Conversation so far:
When did Roger Clemens join the Red Sox?
Roger Clemens joined the Red Sox in 1984
Was the Red Sox Roger Clemens' first team?
Yes, the Red Sox were Clemens' first MLB team
What is something interesting about Roger Clemens' time with the Red Sox?
On April 29, 1986, Clemens became the first pitcher in Major League history to strike out 20 batters in a nine-inning game, against the Seattle Mariners at Fenway Park

Question: What was his average during his time with the Red Sox?
Self-contained rewrite: What was Roger Clemens' average during his time with the Red Sox?