Anyone that has played league for a few years will tell you that it is all about the money for the good players, and fun times for the lessor players. Any good player will tell you that if you set too high an average to begin with, that it will punish you later on in the session, or in the playoff tournaments.
Handicapping is good for participation, but to a certain extent it is detrimental because it decreases the desire in the lessor players to become better, i.e., someone that is a top 5 handicap (like a 5.8 or 5.9) will be more comfortable there than becoming a low 6 (like a 6.1 or 6.2) in a league system, even though there skill level would have increased because they will win more games as a 5 than a 6 because of the 'spot' handicapping provides.
In better players (usually the ones that gamble) their 'money' skill level will be the truest indicator of their true skill. In lessor players you do not have that.
No one system is all complete or encompassing ...
Here is my suggestion:
If one barometer has to be used, then I would suggest using a 10 ball
average. 300 is possible in 10 ball and can be coverted for BCA (75 for 5 man, 60 for 4 man) or VNEA (13 here locally).
Then to prevent sandbagging, I would make all players pay $10, play 1 game of 10 ball, and pay back 10 cents for each point over 100, 20 cents each point over 150, and 50 cents for each point over 200, and $1 for each point over 250. The idea is not to make or lose money doing this, but to just about break even when all players had completed this, lessor players and better players. The 10 ball averages would be converted to BCA, like a 120 average would convert to a 30 5 man BCA average or a 24 4 man BCA average. A 244 average would convert to 61 5 man or 49 4 man (rounded).
Next, you consider average competition level of the league by taking the average 10 average for the whole league. Say, it is 130. Convert it to a
26 4 man average BCA or 33 5 man average (rounded).
If the individual's averages are above the league averages (61 > 33), then reduce the individuals average by 10% (competition factor) to equal 55 for 5 man, 44 for 4 man.
If the individual's average is below the league average (30 < 33), then reduce the individual's average by 20% (competion factor) to equal 24 for 5 man, and
19 for 4 man BCA.
Note: rule is that better than average players averages will be affected 10% by competition (10 ball has no competition like 8 ball or 9 ball), and less than average players averages will be affected 20% by competition.
Averages can be self adjusting afterwards as league play continues.
This is the fairest way I can think of, provides incentive to not sandbag (money paid back when setting 10 ball average for higher average), converts to particular league system, and adjusts fairly for better and lessor players for competition factor. Then moves up or down as league play continues.
Note that 10 ball average would only have to be set once even if player played in league on 4 different nights as it could be compared to a particular nights league average to adjust for competition factor. Say a player had a 45
BCA 5 man average, and 3 league nights average was below that, then the players average would adjust to 40 (4.5 rounded to 5 subtract from 45), but he played in an advanced league where the league average was 50, then his average for that night would be 45 * 20% = 9 from 45 = 36 average for the advanced league night. (most players would be better than him, probably beating him, and holding his average lower than would normally be).
I am open to suggestions, but consider mine first ... okay ...