This is a discussion on % Villain's AA probability % within the online poker forums, in the Learning Poker section; My hand is Ax, one ace lies on the desk.
What ??.??% probability of villain having AA:questionm
:hmpf: Idk how to calculate it
The probability of villain's first card being an A is as you've said above 2/45 =4.4%. But now you've removed another A so only one left, so for villain's second card it's 1/44 = 2.2%. Then multiply those to get 0.1% probability that they have AA
If its on the flop, there are 47 unseen cards, which gives 47 x 46 / 2 = 1.081 combos, of which only 1 is AA. So not exactly 0,1% but pretty close. Also this is ignoring the fact, that action took place preflop, and that most opponents dont see the flop with all those 1.081 possible combos, because they would have folded combos like 74, 83, T2 etc. In the hand, you shared, SB raised OOP against a limp, and he probably does that with something like 200 combos at most rather than 1.081.