[httassadar]

This sort of problem continues haunting me.

Should the K or Q on board change the probability of your opponents hole cards? I think to figure out the probability of his holding K or Q, all 8 cards are counted. His cards are dealt before the flop/turn.

Same as the well-known car-sheep problem? Behind three doors, one car and two sheep. You pick up one door and then shown one other door which is a sheep. Should you change to the third door to get a better chance of car or it makes no difference?

Back to poker, if the flop are 3 spades, and you want to calculate the prob that he made flush. The Bayesian prior should be 13C2 / 52C2, not 10C2 / 52C2 right?

To make things worse, I think your hole cards should count. Ie, hero's pair of ten would increase the probability that his opponent gets Q or K.