This is from bowl.com when you look up averages.
"Adult averages with less than 21 games or youth averages with less than 12 games are not officially recognized by USBC. "
This is from the Rule book:
118c. League Entering Average
Entering averages are determined by league rules. A bowler who does not have an entering average,
or until they meet the requirement(s) defined by league rule(s), average is determined by dividing the
total number of pins by the total number of games bowled the first league session. (See Rule 100g
for handicap.) When a bowler fails to complete his/her first game in order to establish an average, the
frames bowled will be declared null and void and a vacancy score used.
NOTE: The following are options for entering averages:
1. Highest Average: The highest average in any USBC league in which a player competes in
one season.
2. Composite Average: The average of a bowler who bowls in two or more USBC leagues in a
season. The average is determined by adding the total pins for all of the leagues and dividing
the result by the total number of games bowled in those leagues.
Most leagues that i've seen use last years league average which was usually the minimum of 21 games average, But according to the rules the league could set another figure.
For USBC Tournaments USBC Rules:
319a. Conditions that Apply
The following conditions apply to averages in handicap or classified tournaments, unless the
tournament rules state otherwise, except that only USBC league averages shall be accepted. (See Rule
319c for average adjustment.)
1. The bowler is required to submit the previous season’s highest average of:
a) A single USBC league average based on a minimum of 21 games; or
b) A composite average of all USBC leagues, including leagues with less than 21 games bowled.
