Thanks for that link. Interesting.
Sadly this system does not work well enough for curling, imho. It's is way to easy to accumulate a big rate by solely playing players rated 0 or somewhat above 0. This results in crown holders often not being the best players around. I held the crown for a while (by playing equally rated opponents) and I have no problem giving it up. Yet it does aggrevate me to see players never playing any of the brown, yellow, blue or green players. Be my guest to take my crown - but then you should bloody be able to beat the former crown holder!