Conversation so far:
What was significant about the MLB 1962 season?
In 1962, the Dodgers moved from the Los Angeles Coliseum.
Where did the dodgers move to?
Dodger Stadium
How was Dodger Stadium pitcher-friendly?
It had a 250-foot left field line.
What was wrong with the hitting background of Dodger Stadium?
The new park had a large foul territory and a comparatively poor hitting background.
How did moving stadiums affect the Dodgers team?
Koufax was an immediate beneficiary of the change, lowering his home ERA from 4.29 to 1.75.
Did Sandy Koufax continue his no hitter streak during the 1962 season?
On June 30 against the expansion New York Mets, Koufax threw his first no-hitter.

Question: Why did his finger become numb?
Self-contained rewrite: Why did Sandy Koufax finger become numb?