counting opponents

We all count our own outs, does anybody count their opponents outs ie;

there are FDs and SDs on the board that you don't have cards to draw to, they are the outs against you.

What is the best way to use that information?

Thinks it happens too fast to count OP outs specially if you multi tabling so the answer is no.....

Could we say the more opponents in the hand the more collective outs there are therefore there is less chance we will make our hand if we are drawing to say second best pair or an inside straight.
Best policy would thus be fold to action or alternatively raise substantially to force drawing hands out.

You need to practice more and more. This skills involves logical thinking and you need to have a lot of experience. It is not always impossible to know or to predict opponents hand. But if you habitually do counting outs, you might eventually good at it.

No. We don't count unknown cards (opponents cards, burn card). Now if someone goes to muck and exposes a card you can count it (or discount it) but otherwise, no.

This is what i'm referring to originally by Tony G:

"Your opponents’ hand distributions don’t affect the probabilities much unless all the hands in an opponent’s distribution contain some of your outs. But even when their entire hand distributions count against you, you can make an on the fly estimate and subtract something like 3%-5% from the winning percentage you’d get if you put your opponents on random hands. So go out there, read your opponents, and be confident in the math governing your drawing hands."

Something like the third king that makes you trips making a flush or straight for an opponent so even though it is an out for you it can also make another players hand as it is an out for them also?

Are you wondering about clean outs?

Drawing to straights when the board is two tone and drawing to flushes when the board is paired can be problematic for sure. You have to be careful when your outs may make your hand second best. Same thing goes when your drawing to the dummy end of a straight.