In English, the name of a game or sport is usually uncountable.
Example: Hockey, Dodgeball, Baseball, Soccer (all uncountable)
The objects used in the game or sport are countable.
Example:
A dodgeball - is a singular countable noun which requires a determiner.
Dodgeballs - is a plural countable noun which does not require a determiner.
If you want to play dodgeball, you must pick out a dodgeball from the bag of dodgeballs.