I bowled in a league that did this exact thing. Used the average of the highest league bowler from the season before. Got stupid in the end. We had a bowler (wont name names) that averaged 232 for a 27 week season. The league voted to change the hadicap sytem from 90% of 220 (the previous seasons) to 90% of 230.
Not only did that bowler leave, but so did the team, and 4 other teams as well. It became that if you averaged well, you got penalised for it.
Lets face a fact here, a bowler who averages 200 plus, is bound to bowl games around that mark even higher, but to score a lot higher is not that regular. For bolwers around the mid 170 to 180 mark, they on a regular basis will bowl a 200 plus. They will beat the 200 average bowler on a regular basis due to this fact. The bowler who averages in the mid 170 bracket will bowl just as many if not more games over average over a season than a 200 to 210 average bowler. (When you look at they bowl over thier average this will be more than the higehr bowler on average)
In the league l mentioned above, they are down to 14 team from 28 as the higher average bowlers have moved on, as they could not be competitive in the league due to the handicap system. No high average teams won the league seaason in season out. It was mostly the 175 to 180 average teams that won this league on a regular basis, as they were able to bowl more over average on a regular basis than the high average teams.