ChipD said:
There's talk about starting a straight pool league in our area. ...
The system used around here and in some other places is simple at its core: Players get ratings, the higher-rated player in a match has to make more balls to win than the lower-rated player, and the ratings are adjusted after each match. The winner goes up and the loser goes down. All of the handicaps are determined by the difference in the ratings of the players. If two players are 100 rating points apart, the handicap will be about 2:1 on points. In the league I play in, there are players up to about 300 rating points apart, and such a match would be 140:20, typically. Yes, players really are that far apart, and that is a fair match.
The details are in the rating assignments, the rating adjustments and figuring out fair matches.
For starting ratings, make your strongest player an 800, and work down from there. If you have any idea of how many points he would have to give up in a fair match against other players, those other players can be given ratings that would produce the fair match.
After each match, the winner goes up 3 points and the loser down 3 points. You can make larger adjustments to new players and the first season, but you better have it all in writing or players will feel you are treating them unfairly or doing favors for your friends. You might want to adjust by 10 points per match in the first season, but you run the risk of overadjusting. Also, for brand new players in an established league, you need to reserve the right to do arbitrary adjustments the first few weeks of membership.
Other details are discussed in
http://www.sfbilliards.com/articles/2003-06.pdf but the adjustment method in there is no longer used -- use the system above.
Tables of matches for various rating differences are listed at
http://www.sfbilliards.com/14.1_charts.htm Note that you can have two weak players go to a lower total than two strong players so that all matches take about the same length of time. Where I play, the stronger player may go to 60 to 140 depending on his rating, and then the weaker player goes to something below that according to the tables.
One additional thing to consider is how to treat/encourage the better players. The system as described is guaranteed to produce fair matches -- that is, close to a 50-50 proposition for both players. Some of the top players don't like that. You can have a special "masters" tournament at the end of the season for the top 10% of the rated players with some fraction of the season's prize fund. I think this is a better solution than trying to build in a bias to let the top players win more games.
