I do this for work (in the games industry) so I might be able to offer some advice here.
Why not institute an Elo-based ladder system?
For those of you who don't know what an ELO ladder system is, here are some general characteristics. There are variations of course.
Rankings are determined based on your wins and losses against similarly ranked people. Wins against higher ranked players will increase your ranking while victories against lower ranked players might yield smaller positive gains. Losing against a lower ranked team will decrease your ranking. The basic idea is similar to the Elo rating system used for professional chess. (modified from WoW arena description).
- * At the beginning of a season, players are all assigned skill values. This starts on par for all players.
* People are ranked in a ladder from highest to lowest skill values. Higher is better.
* As players win or lose matches, gain or lose skill points
* The amount of skill points you gain or lose in each match is dictated by the relative skill values of the two contenders in a match. This rewards people for winning against better ranked players, and penalizes for losing against weaker player.
* For example, if I am challenging someone who is much much better than me, I stand to gain more points in the match if I win, but lose a nominal amount of points if I lose. The person I challenge who is stronger than me will gain less points in the match if he loses, but will stand to lose more points if he loses to me. If I challenge someone who is ranked the same as me, we are on par with each other and both stand to win and lose the same amount of points regardless of outcome.
* Players can play each other as many or as little as they want.
* You can play whoever you want, as often as you want, and the ranking system should reflect your true skill level.
* World of Warcraft uses this for arena PvP ranking.
* Xbox uses this is there TrueSkill ranking system.
* Battlefield uses this.
* A lot of sports games uses this.
This is a great way to do it because there are no single-match limitations per player as in a round robin format.
This is also better than a bracketed system because those handles an odd number of players better -- single elimination style brackets require you to have an amount of players that number in a power of 2. For example, 2, 4, 8, 16, or 32 players. If you have an odd number people, you need to go into a system of "buys" (where people have to sit out in matches) or double eliminations, which are a pain to manage. This system is not desirable because there is a lot of admin overhead, and you need players to schedule matches.
I really wish they instituted something like this in the VOOT online play. What they have right now is a VERY distilled down version of this, but I guess it's better for casual players. It allows people that suck (like me) to still get climb their way up ranks -- it's just a grind and takes much longer.
The trick now is to find a place to host a ladder if you are all interested. I can do some of this research. Gamebattles.com hosts a lot of ladders, but I need to inquire to see how we can make a VOOT ladder.