Your average is then recalculated each week according to the number of games you have bowled. This means that at the begining of a season you will possibily see more fluctuations in your average (and hence your handicap) than you do later in the season. As a League Secretary this is one of the hardest concepts for some bowlers to grasp.
If you have a really good night early in the season you will see a spike in the numbers and it always seems that it takes longer to go down than it does to get higher - perception is a wonderful thing.
Some centres have preprinted cars that track the date, games, series and cumulative pin fall allowing you to keep a track of your own average, and watch it improve. Your League Secretary should provide you with the formula that the league has determined it will use - this would normally be set at the League formation meeting and recorded in the constitution.
Good luck and I hope you enjoy tracking your improvement.
Cheers
Janey