WGTadmin, I believe that's a serious mistake you're making. That's exactly what we have been warning you about. Please reconsider and do not implement it in this way.
If you do what you describe above, the reputation score will be useless. You will be punishing the quitters' victims along with the quitters.
You see, when I want to play a multi-player game, I want to play a multi-player game, not single-player! Just try it sometimes, WGTadmin: join a dozen random-pickup multi-player rounds (but not as WGTadmin; as a regular-joe beginning player), and I guarantee you all or most of the rounds will fall apart after a few holes played. Do you have the time or inclination to finish all of those rounds by yourself? Nope. That's not what you wanted.
I believe it would be better to have no reputation scores at all, than scores that would be as seriously flawed and unfair as suggested above.
Please, when someone is left alone on the course, automatically consider that round single-player, giving that deserted player the option to quit the round without any penalty.
Thank you for giving this a thought.