I asked this question under the Beginners Questions and it'd be better to ask here. What is a poker theory and does anyone have an example of it? I've heard people talk about it more recently and I've never known what it meant.

I dont know what else to say other than poker is inherently theory. This poker theory is what enables us to play either a GTO or exploitative style of poker. What style you want to implement is up to you completely. Ill try to create an example, hopefully I dont botch it badly.

Lets say for ex we have a hand like JJ and board runs out 9Q875. In a GTO approximation the correct play is known and if we use that strategy we cannot lose long term. However, with exploitative style play we can deviate from GTO and try get value or alternatively reduce our losses. For our example here lets say our river GTO play is check call, but our exploitative best play may be either to check fold, or to just bet the river.

Hope that helps clears some of it up, cheers

Poker theory relates to how and why we make a play. The logic behind the strategies that we adopt.

Poker players nowadays are real advanced in regards to strategic theory. They have broken theory down into two main groups. Exploitative and GTO... GTO is Level infinity, exploitative is the other levels.

How is your 3d level of thinking stuff?
(sorry, cant remember the exact term)

GTO is not level infinity. Not at all.

Its the set of ideas backed up by mathematical and empirical evidence that guide the way we think poker should be played.

Here's my poker theory:

1) reciprocal events: any time you play a hand exactly how your opponent would play that hand, nobody gains.

2) non reciprocal events: any time you play a hand more profitably than your opponent would play that hand, you gain; any time you play a hand less profitably than your opponent would play that hand, you lose ev.

3) profitability: the average fraction of the pot that you receive in the long run. If two players are making good decisions, the range vs range expected values will be <(pot) for both players. If players are making - ev decisions, the expected values may exceed (pot).

4) equity: the likelihood that you will win the pot.

5) risk vs reward: an extension of profitability. The lower the risk and the higher the reward, the more likely it is that you have a profitable investment with more and more of the combos in your range. The higher the risk and the lower the reward, the less likely it is that you have a profitable investment with less and less of the combos in your range.

6) investing: this can mean the act of buying into the game, but to extend upon that, it also means the act of putting your chips in the pot. Since folding is free, this means that if you're playing correctly and therefore investing correctly, then you should be making zero plays with negative expectation; you should be making nothing but profitable plays.

7) variance: the bigger your bankroll, the more you should protect it from variance by putting up small chunks of your bankroll. Google variance calculator and have some fun with it.

8) psychology: it's just a game. it's supposed to be fun. I had a baseball coach when I was young. He would say, "practice hard so you can have fun when gametime comes." I agree with that.

9) extensions, cliches, and random droppings:

9a) when it rains, it pours. An extension of variance. Sometimes you can't win. Sometimes you can't lose.

9b) if you spend all your winnings, your probability of going broke aproaches (1). - unknown

9c) value betting: just do it.

9d) bluffing: just do it.

9e) bluffcatching: it's tricky. Fold junk, call strong bluffcatchers, act on reads with the in between stuff.

9f) slowplaying: works like a charm vs overaggressive overbettors. Sucks vs passives.

9g) the free card: free equity = profit.

9h) balance: just a byproduct imo of correct poker.

9i) mixed strategies: good vs good players, bad vs bad players.

I'm sure the list goes on but I'll stop there.

Lol I think it's safe to say that my understanding of the Levels has changed a lot since I was last here...

I've been away writing that book I promised. And while working away I found out so, so much about theory.

It's not solely a poker book anymore. It's a general strategy book. I'm pretty sure I've mapped out the way the mind calculates all decisions. And so I'm pretty sure I've found the boundaries surrounding all comprehendible strategies.

Or maybe I've gone completely insane lol. We'll see soon enough. I've finished now, just waiting on my editor to do his last run. It'll be out in a couple of weeks.

how would one calculate their standard deviation?

Most poker trackers will calculate it for you. If you're playing live then it becomes somewhat more complicated, unless you keep good track of how much you are up or down for every unit of time you play for.