I know this has probably been covered a million times, but my dad and I are thinking about trying to get our winter league (8 team league that mostly consists of low average people) to move from 80% to 90% handicap to adjust fairness across the teams. I never really saw this as much of an issue before because I have always been on the competitive teams in that league and have always had the most points even when my team didn't win the league. On this summer league however, a team has come in with all high average guys and the handicap at 80% is not enough for any team to touch them. I see what my teams have been doing in the winter league from the other side of the perspective and want to make it more fair. Thoughts? I also know the argument that other bowlers can get better if they want to win, but sometimes there are physical limitations

My current league is 90% of the difference between the total of the team members' averages.

Last night our team was giving the other team 207 pins PER GAME (712 vs. 482).  We still won 2 out of 3 games.  The game we lost was only by 40 pins.  Two of us struggled that game...had we bowled our average we would have easily won.

This is what I prefer.  And it isn't any different than basing the handicap on the highest average in the league assuming no one ever averages higher during the year. (also works out the same with a 300 base).

It all comes down to presentation.  We bowlers are not too bright at times.  If the high average in a league is 220 and you base the average on 230, then everyone gets handicap.  So changing it to 225 or 250 doesn't change the outcome but it might change the perception.  Some high average bowlers see handicap at 90% of 225 (avg 220) and feel a certain way about their 4 pins.  Change it to 250 and they now get 27 pins.  Doesn't change the outcome on a game-by-game basis but they might feel better getting the extra 23 pins.

I agree with the 90% of the differences between the team's averages. 

If you're going to bowl handicap, ditto……
 
Anytime you mix low average bowlers with high average bowlers, and try to come up with something that's "fair", you're doomed. These handicap threads pop up like relentless weeds because there are too many variables to come up with a system that isn't fatally flawed.
 
The best system I've participated in on fairness is team capped scratch, with a limit on minimum average. It's not perfect, but assuming the entering team averages are realistic, and teams are constructed close to the max, you have fair competition without all the nonsense associated with handicap formats.
 
Unfortunately, when you use the word "scratch" in any context, the majority of league bowlers run for the exits. The irony is that most bowlers who try capped scratch have a hard time going back to traditional handicap.

Think a lot depends on the bowling population you have to draw from. Our area has 2 centers and approximately 1500 sanctioned bowlers. We have a league in each house that is individual scratch, but 100% handicap bases on difference of teams averaged. Both leagues were capped at 800 and one league had 14 teams, the other had 8 (on military base with 12 lanes) the league downtown removed there cap because the team with highest average whined because they did not want to bowl with anyone else. That league is now down to 6 teams and the league on base with same format that is capped is now at 12 teams. Lower average bowlers were tired of paying $16 to get ass whipped every night. Sometimes not catering to the higher average bowler is what brings business and fills leagues.

 
Managing any league with a team cap requires discipline. At the end of the season, you have to recalculate next year's max based on current team averages, and establish a number that's best to sustain the league.
 
We recently went through that process, and this year's league champion whined that they'd be over the new max and have to break up. They threatened to leave unless the max was raised to fit them. They were politely shown the door and will not be back. Apparently, the leagues in your area didn't do the same.
 
Caps work well if they're managed correctly. You gave a perfect example of why they sometimes don't.