Wow, that's crazy.

It seems like it would be easier for AI to do, since it doesn't have any tells (it's easier to have a poker face when you don't have a face at all).

I remember playing poker as a kid, and experimenting with pretending like my cards were good/bad with body language. I don't think that any professional players use that approach (they just have sunglasses and a straight face), but I wonder if AI could beat humans even more consistently if it developed a way to convey tells and fake tells?

All Poker AIs developped as yet approaches Nash Equilibrium -- it's just a "perfect" strategy that wins by default because it makes no mistakes. Since you make mistakes against the AI strategy, and the sum of the game of poker is 0, you lose by default.

No poker bots yet I know of have developed "exploitative" strategies, where they deviate from the Nash Equilibrium strategy to exploit opponent mistakes.

Back when I played professionally (2012-2016, poker AIs being relevant in 2015/16) the standard was to use a bot to study the best default strategies and use expert human judgement to deviate from it against bad opponents.

Nash equilibriums exist when bluffing is involved?

It seems like it would introduce a level of predictability that would make it easier to know when the opponent is bluffing.

They absolutely do. Since it's world cup time I'll use a contrived soccer example.

A penalty kick where the kicker can kick left or kick right. The goalie has to jump one direction, if they jump the wrong direction a goal is scored. Both people know that this kicker is great at kicking to the left side of the goal but rather "meh" at kicking to the right, so if the kicker kicks to the left and the goalie jumps left, there's still a 20% chance of scoring, but if the kicker kicks to the right and the goalie jumps right, there's only a 5% chance of scoring.

There is a Nash equilibrium for the kicker, and it can't be "always kick left" because then the goalie would "always jump left" which would give the kicker an advantage if it kicked right.

Similarly the Nash equilibrium for poker can't be to always fold a weak hand, because that's leaving money on the table because then the opponents will always fold against a raise, which would mean the player could get easy money by raising with a weak hand.

> Nash equilibriums exist when bluffing is involved?

In some sense that's the whole point of Nash equilibria.

A strategy can involve probability, like bluff 30% of time.

Bluffing isn’t really something one needs to compensate for. Bluffing as a game rule simply means that all hands or values may be max or min values, but the idea is that if you are making bets based on the mathematics of your hand itself this isn’t so pertinent.

There is a new player in the professional poker scene that people call "Casino Eric". He combines reverse tells with insults and jabs at the opponent. This helps him make up for a lack of pure technical skills when compared to top online players like Linus Love. This is a meta game that people have played for a long time, but "Casino Eric" is known in professional circles as someone who is naturally trying to perfect this.

Unless it's completely random, you're just giving away information. i.e. do the opposite of their body language, only exhibits body language when it's really bad or really good, voluntary vs involuntary body language.

You only use the "tell" when you believe there to be a pattern.

Otherwise, if it is truly random, I realize I can't get any info there and I ignore it, which then leads to me just having a straight face.

Is that heads-up only? Early massive overbets are nearly a coin toss in heads-up, so you break even in on a call and win on a fold, which is an equilibrium.

However at a large table, you are going to get called only by the person who thinks they have the best hand, which is a lot better than the average hand of a typical opponent.

This is mostly done at the river where you've ended heads-up even when starting the hand with 6-10 players

Its more common in heads up, yes.

In multiplayer you see it where ranges are narrowed, like 3bet pots or on turn/river

It matters less than you'd think because overbets imply you have a polarized range (nuts or air). You generally pick the bluffs to be hands that have cards blocking the best calling hand combinations.

Okay, that makes sense. I think it matters some still because if someone else has nuts, then they automatically know you are bluffing, and the more players still in the pot the more likely one of them has nuts.