The heated debate on whether poker or chess is more complex has been talked about extensively over the past decade.
Anyone who is interested in this debate should read through the 15 page thread on the twoplustwo poker forum.
Many skilful poker and chess players are voicing their opinions on the forum; although, the debate does seem slightly bias towards poker, after all, it is a poker forum.
It is important for us to define complex before trying to figure out which game is more complex.
Complex as an adjective: “consisting of many different and connected parts”.
Complex in mathematics: “denoting or involving numbers or quantities containing both a real and an imaginary part”.
Let us use these two definitions to define the complexity of the game.
Based off the definitions, another way to state this question would be: Which of the games have more variables?
Chess displays complete information, but poker displays incomplete information. So, this means we have to take the imaginary part of complexity into consideration.
Poker’s imaginary quantities are far greater than chess, since chess has no imaginary quantities and everything can be seen.
You cannot exactly quantify the amount of imaginary variables, e.g. bluffing about bluffing. So, you could say poker goes infinitely deep in regards to layers of psychological games.
However, in terms of concrete variations. Chess easily takes the cake.
When we focus on the sheer number of variations, an hour of playing chess is vastly more analytical than a hour of playing poker.
Chess may require vastly more memory about past situations on the chess board, and how they apply to their current position.
But poker requires memory in a different way. Poker players have to remember patterns of their opponents from hundreds of hands ago, and exactly what their opponent did in a given situations.
This is pattern recognition of players, not pattern recognition for the game itself.
Many chess players switch over to poker because of the potential poker has to make money. Chess games are usually not for money. However, this does not take away the complexity of chess. It is still vastly more complex than poker.
The element of complexity in poker is in incomplete information. But this is more of a subjective complexity, because it does have infinite depth when you factor in betting patterns.
Chess complexity is more apparent and concert. It has complete information with trillions and trillions of possible positions. There is no need to add the factor of complete information.
The real complexity tree of chess is estimated to be 10 to the power of 120. This conclusion was made more Claude Shannon https://en.wikipedia.org/wiki/Shannon_number, (this is a.k.a. Shannon’s number).
The actual amount of reasonable positions is closer to 10 to the power of 40.
You can see the level of analysis that chess world champion Magnus Carlson into in this video.
Quite different than a poker video!
Lucky for us poker players, we don't have to work as hard as a chess grandmaster to make some quick cash.