Most tournaments continue to accept only averages of 21 games or more for handicap purposes.
However, a local association is now required to submit all averages, regardless of number of games. Reason: If you now look at a USBC member's average on bowl.com, you will see that if he/she has bowled in more than one league, a composite average is now listed (and it factors in all league averages, regardless of the number of games bowled).