Simple combinations.......

[Schizo]

Say the odds of UTG having KQ is 1/34 and the odds of MP is 1/8 depending on the action/PT stats.

What are the odds we are up against KQ? Is it 1/8 + 1/34?

[numeri]

Close. You need to subtract the probability that they both have it since you counted that twice. More formally, let

A = UTG has KQ
B = MP has KQ

P(A or B) = P(A) + P(B) - P(A and B)

The trouble is finding the probability of (A and B) - they both have KQ - is not easy to calculate. If the two events were independent, we could multiply them. Unfortunately, they are not. (If UTG has KQ, then MP is less likely to have it.)

In practice, the probabilty that they both have KQ is fairly insignificant, so we can probably ignore it and end up back with your original calculation. /images/graemlins/laugh.gif