# that there would be no perfect strategy for poker

In my opinion, every imperfect information game where there is the possibility of bluffing lacks a perfect (or winning) strategy, for the simple reason that knowing your opponent's strategy will let you beat him easily (even if his strategy isn't 100% deterministic).

So why do the guys that developed 'Cepheus' claim that they made a program playing poker with a perfect strategy, claiming that their AI 'is guaranteed to not lose money in the long run' ?

I'm pretty sure I can create a strategy winning versus Cepheus, because I know its strategy.

Where am I wrong ?

• the media did not report this very well, but basically cepheus computes nearly perfect statistics of the game (or statistics within an extremely small error), which is very complex and requires nearly supercomputing level resources to calculate. the real game involves a lot of other factors such as noticing patterns in opponents play. the point is that even if you did know Cepheus's entire code, you could only tie it at best over many games.
– vzn
Commented Sep 7, 2015 at 1:23
• I could get only a draw in front of him on the long term ? this is what I don't understand : if I know how he bluffs (or doesn't), I can bluff him more, and better, so that I should be able to beat him on the long term ? and we agree, we talk about real-life poker with limited money and betting. Commented Sep 7, 2015 at 1:29
• @vzn for me, poker would be like the prisoner dilemma : if you know your opponent's strategy, you can easily beat him. Commented Sep 7, 2015 at 2:40
• try thinking about it this way. with perfect strategy the game becomes like a coin flip. can you consistently win at coin flipping also, even knowing your opponents "strategy"?
– vzn
Commented Sep 7, 2015 at 2:42
• no sure, that's why I mentioned bluffing in my post. the probability your opponent is bluffing at a given moment is unknown, but the more you approximate it well, the more you can counter-bluff and win. Commented Sep 7, 2015 at 3:18