This would be an alternative to picking maps before games. Registered players can pick a favorite map and a least favorite map on the stats page. This would influence the choosing of the map they play on.

Say that there are ten hypothetical maps in the rotation, maps 1 through 10. Map 3 is this fantastic map. So in this 4v4 game, 2 players from the red team and 2 players from the blue team have map 3 set as their favorite map. This makes it more likely that map 3 will be chosen from the ten maps.

Map 7 sucks. It's not even creative. C'mon, take it out of the rotation already. 4 players have this as their least favorite map. This makes it less likely that map 7 will be chosen.

The other 8 votes (remember, favorite and least favorite for each player) offset each other for the other maps, so the only change in the likelihood of any map being chosen is 4 for map 3 and -4 for map 7. So now the likelihood is 14% for map 3 and 6% for map 7.

Obviously, the numbers are just things I've thrown out there for the purpose of the explanation. This way there would be no quick picking of a map before games, it would just go straight into the game with the chosen map already there. Maybe the map isn't revealed until 2 seconds before the start of the game so that the map can be chosen as people are still joining?