I think .66 is substantially too low. Iyama Yuta is well over 50% against any professional in Japan, and while Ishida is still competitive in Japan, he's not a

I think .66 is substantially too low. Iyama Yuta is well over 50% against any professional in Japan, and while Ishida is still competitive in Japan, he's not a title contender anymore. So I'd wager that Iyama is at least a 66% favorite against Ishida, and Iyama is himself not 50-50 against the absolute top players (40-60 perhaps, maybe worse).