Penalize poor sportsmanship. Leaving a game because you are going to lose is not fair to the other player and it seems like the same group of people are the ones doing it. Put all of them in their own section.
I'm not talking about losing internet connections, just the ones just leaving to screw the other player out of their rewards. It's not okay and that is the only thing I HATE about my Favorite Game.
Have a Sweet Day