Poker-AI.org

You've seen the thread on solving the river on the fly with a preexisting strategy, now you do you solve the preflop with preexisting post-flop? Is it just as simple as probing to the leaf nodes then returning the utility?

yes, you can consider the flop as a terminal node and launch a CFR just adjusting the preflop strategy, but there is a big problem : the pre-existing postflop strategy(and utility) depends on the distribution ranges of preflop holdings.

I can probe to the river with my existing strategy, and return the utility I land on there. The question is, is that enough?

I am a total newb when it comes to understanding what CFR or any other of the stuff mentioned here but everything depends on the accuracy of the preflop range you assign the villain. If you can solve preflop then post flop gets way easier because he is either betting for value or he is not. It gets easier on every street to narrow his range but if your initial range is off then its a crapshoot and your range equity could be way way off. Preflop is the key to everything.

How you do that without the flop?
Convergence must be bilateral, on each iteration, the preflop & the flop converge to a nash because both are inseparable (preflop you need the postflop utility, and the postflop utility depend to the preflop range)

I am using a rule based system and not trying to nash solve anything. If you can accurately determine what his hand range is based on his preflop stats then postflop becomes much easier imo. I am thinking that it is only possible to get something in the 65-70% area tops even with quite a bit of historical data on the villain.

Lets assume your facing a new villain and he is raising 80% of buttons HU. So you call the raise and the flop comes Qh8d4s. He c bets and you call and the turn comes a Kh and he leads again.

At this point he is still betting with 100% of his range but he can only be value betting AA, sets, two pair and Kx. Everything else is thin value or a bluff (which is a huge part of his range at this point). Any thin value hand you could potentially get him off of so they are not too much to worry about. So now you can remove all the under pairs including Qx from his range and keep in any gutters and open draws.

The river comes 2s and he leads again. So now you rerun equity leaving in all the busted draws and removing any other non value bettable hands in his range. At this point you have narrowed his range to a very small number of hands.

Sounds easy right? not so much. The key is preflop and getting his range correct. For a player who has polarized his range figuring this out is extremely difficult. Without seeing a bunch of showdowns you will never really know what hands he may be 3 or 4 betting with. Every player is different.

The only solution I have found is to 3 and 4 bet quite often to narrow his range down preflop as much as possible. Many players will not 4 bet or shove with garbage. Maybe somebody like isildur would however...

We talked about nash; your rule based system will be exploitable.
If you want a strategy that exploits the opponent leak without being "too exploitable" there are other algo (DBR, RNR,...)

Its only exploitable if its not polarized and its actions not randomized. Its really not that difficult to confuse the villain and remain unexploitable thru rules. You just have to avoid doing the same thing all the time. You want them to think you could have anything at any given time.

The key to exploiting an opponent leak is usually thru pure aggression. They either adapt to you or they let you run over them. So you force them to make the decisions and not the bot. And if they do adapt then there is not much $$ to be made and you should quit and find another player. Its really that simple. Like many pros the bot generally needs to become a bumhunter of sorts.

You just have to find out early what they will do in certain situations that come up often. One such play is the flop goes check check and the opponent leads out to steal the pot. If your bot is keeping detailed stats on this type of stuff the next time he does it you hit him with a raise and see how he reacts regardless of what the board and hand is. I have many such plays that are used for "probing" the villain to gain information. Preflop is usually the place to start this. How does he handle a 3 or 4 bet? There comes a point in which your hole cards mean nothing and your playing the player. Preflop is of course better to do this on not only because its cheaper but you can also narrow his range by quite a bit. Its very important to get information on the type of player he is right away as this will affect many of your post flop decisions like stealing.

Anyway..I understand the NE stuff and its really cool. I just dont know if its possible to solve a 100BB+ game anytime soon but maybe.

Anyone solve it yet? with CFR?