My math logic is flawed right now, maybe because i'm tired, but help me out on this one.

KQ vs 79

Flop: 268

So the 79 has 12 outs. 3 5's, 3 10's, 3 7's, 3 9's

12 outs twice, is 45%. Why is it 35% vs KQ

Help me with my flawed logic.

What happens if the turn is a 7 and the river a K?

That's fair. So if we are trying to make a real time rough calculation at the table, what cheat code should we use to discount our outs (equity) assuming our opponent has 2 overs, and we hit our out on the turn, only to get re-hit on the river?

If you're facing an all-in you need to estimate your equity against the range you think he'd go all-in with, not the hand he ended up having.

This particular hand is almost always going to be fine to GII.

Well let's say we can see our opponents cards face up though. So we know they have exactly 2 overs.

The general rule of thumb is 1 out = 2% equity, 4% if you get it in on the flop and are able to see the turn and river.

I want to know the quick way to discount %'s when we know our opponents can hit better outs?

tldr, whats the quick way to calculate that our equity is only 35% in this example instead of 45%?

There is no easy answer to your question. Estimating equities is a valuable skill to have in all forms of poker. And, as pointed out above, equity is most often considered in terms of ranges, not specific hands.

There are no generically useful quick-and-dirty rules of thumb for estimating the equity of "dirty" outs since there are so many different situations that arise in poker. After one plays enough poker, especially in tandem with playing with an equity calculator, one builds "intuition" about different equity situations.

Anyway, one way to estimate the equities of the two above hands is the following:

1. Villain has 12 outs twice -> 47%

2. Suppose villain hits one of his 12 outs on the turn. Now consider what could happen on the river.

3. Half the time Hero will have 7 outs to win (approx 16%) and half the time Hero will have 13 outs to win (approx 30%).

4. Average of 16 and 30 is 23 (so Hero would have approx 23% chance to win in that case).

5. So Villains 47% needs to be reduced by approx 23%.

6. 47%*(100-23)% is (47%)(77%) or approx 36%.

Of course, this is not exact and not entirely valid, but as an approx method it is not terrible. You can even round all the numbers so it becomes easier to do the math in your head.

Good luck.

Whosnext’s approximation is pretty cool. It took me a few tries to work out the exact 35% probability.

For some cases, doing a quick calc is easy. For example, suppose you have an open-ended straight draw on the river giving you 8 outs. You are pretty certain villain has a flush draw so two of your outs are “dirty”, using whosnext’s term. So your net outs are 6 giving you a showdown equity estimate of 12%.