NL holdem, 6 max, 100bbs deep.

Hero opens from CO, BTN 3bets, hero calls.

The board runs out as follows.



BTN barrels all 3 streets with standard sizings (one third, two thirds, shove)

Why is CO on the river only calling pure with AQo when the ace is the ace of diamonds, but mixing some folds with all other AQo combos?

If anything, it would seem that having the Ad is bad, because you block some missed flush draws.

having the Ad is good because IP is not going to bluff with Ad in hand, but he will bluff with other Aces, in fact the non diamond Ace is probably the worst possible blocker you could have, so much so that you get to fold AQ when its a value chopper

And IP is not going to bluff with Ad because AdXd is part of our folding range?

Correct

Thanks. I understand the logic, however it is a bit tougher in practice, because there are also spots where our opponent would barrel with some missed flush draws, in which case holding a blocker to that would be bad, not good.

So how do you distinguish between the two in game, are there any helpful general trends or do you just have to drill specific spots for hours and hours?

Lots of variables but to name a few:

- River improving bettors range: they may have to start bluffing all or most air
- Bettor being OOP: they don't have as much variety in turn betting range morphology
- FD blocker being a lower card: Bluffing a low busted fd is generally not terrible, bluffing the Ace high busted fd is only right in specific cases

Try asking the question, "How can my opponent make my strategy bad?"

If you fold AQ with the diamond and call without, villain has a very simple counterstrategy of giving up all his diamonds, and only bluffing without diamonds. Which is what he wants to do anyway, since his diamonds block your missed flush draws. So preferring to call AQ without diamond cannot be correct.

On the other hand, if you call with the diamond and fold without, there is no obvious counterstrategy for your opponent. He could of course start bluffing with Ad hands given that they now block your calling range, but that would be shooting himself in the foot, since Ad also blocks lots of your folds. Which is why the solver prefers calling AQ with the diamond - because villain cannot make your strategy bad.

This also explains why we prefer calling without diamonds in some other lines. When IP is betting 3 streets, he can easily find non-diamond hands to bluff with. But if IP had called the flop and turn instead, most of his air hands are going to be flush draws. This makes OOP prefer check calling without the diamond, because once again, there is no way to make this strategy bad. IP would like to bluff with non-diamond hands that now block the calling range, but lacks the ability to do so. And this in turn makes OOP's strategy a good one.

Watch this 1min video for a more visual explanation:

Thanks