BLS is designed to use a book average or entering average for either the described number of games for each bowler or the number of weeks of the league.
The rule may be configured in the program to use the first 3 weeks of the league, thinking this means the bowler’s first 3 weeks.
The rule is clearly marked as meaning weeks of the league. Once the league is beyond the week designated, the program will no longer utilize the book or entering average for the bowler.
The solution is change the weeks of the league option to games for each bowler option and multiply the number of weeks against the games bowled each week.
The program will look at each bowler to see if they have completed the required number of games before using their real average.