Kuhn Poker Documentation:

[xkianteb]

Is there any documentation explaining what each of the 11 indices in the state space of Kuh Poker represents? I understand the gist of the game, but I need to know what the indices mean -- in order to compare my final models against the Nash equilibrium strategies.

[lanctot]

Hi @xkianteb , the contents of the tensor are encoded here: https://github.com/deepmind/open_spiel/blob/b8c2ff8e9a4f5dad9b179217f740ddb0df967f7c/open_spiel/games/kuhn_poker.cc#L70

Though it is certainly stilo not obvious, we should have an English description in comments there.

@elkhrt @michalsustr I believe one of you changed this, can you give us the plain English description, along with an example? (I will then add it to the code in that spot.)

[xkianteb]

@lanctot Thank you :)

[michalsustr]

Indeed for Kuhn we can put a detailed comment.

Something along the lines of:

  // WriteTensor encodes the observation for the current state.
  //
  // For example, for a state with history of actions "0 2 0 1 1", i.e. after:
  //
  //  - 0: player 0 was dealt card 0,
  //  - 2: player 1 was dealt card 2,
  //  - 0: player 0 passed
  //  - 1: player 1 bet
  //  - 1: player 0 bet
  //
  // the observations can vary, depending on the IIGObservationType specified 
  // in the constructor:
  //
  // - kDefaultObsType
  //   player: ◉◯
  //   private_card: ◉◯◯
  //   pot_contribution = [2.0, 2.0]
  //
  // - kInfoStateObsType
  //   player: ◉◯
  //   private_card: ◉◯◯
  //   betting: ◉◯
  //            ◯◉
  //            ◯◉
  //
  // - kPublicObsType
  //   pot_contribution = [2.0, 2.0]
  //
  // - kPublicStateObsType
  //   betting: ◉◯
  //            ◯◉
  //            ◯◉
  //
  // For more information, please see comments in the observer.h file.

Also I made a program called SpielViz which does this nicely (under the Observations card).

[xkianteb]

For Kuhn Poker with two players; what do the last two dimensions of the state space represent?

Player 1's state space:

0: 1 if the current player is player 1 1: 1 if the current player is player 2 2: 1 if player 1 dealt card 0 3: 1 if player 1 dealt card 1 4: 1 if player 1 dealt card 2 5: 1 if player 1 'Pass' 6: 1 if player 1 'Bet' 7: 1 if player 2 'Pass' 8: 1 if player 2 'Bet' 9: 10:

Player 2's state space:

0: 1 if the current player is player 1 1: 1 if the current player is player 2 2: 1 if player 2 dealt card 0 3: 1 if player 2 dealt card 1 4: 1 if player 2 dealt card 2 5: 1 if player 1 'Pass' 6: 1 if player 1 'Bet' 7: 1 if player 2 'Pass' 8: 1 if player 2 'Bet' 9: 10:

[michalsustr]

9 and 10 are if player 0 passes / bets -- if the sequence is player 0 passes, player 1 bets, then player 0 gets to act again:

[xkianteb]

@michalsustr I am completely sold on the GUI :) Thanks