Counterfactual regret minimization in Go

Implementation of chance sampling counterfactual regret minimization in Go.

Installation

Install with

go get github.com/int8/go-counterfactual-regret-minimization/cfr

Usage

The central struct is cfr.ComputingRoutine which holds GameState interface and global set of StrategyMap (keeping data necessary to compute nash equilibrium at the end)

To use it for your imperfect-information sum-zero strictly competitive two players game (like various kinds of poker) you need to provide implementation of GameState interface.

// GameState - state of the game interface
type GameState interface {
	Parent() GameState
	Act(action acting.Action) GameState
	InformationSet() InformationSet
	Actions() []acting.Action
	IsTerminal() bool
	CurrentActor() acting.Actor
	Evaluate() float32
}

Rhode Island Poker example

Example implementations of Rhode Island Poker and Kuhn Poker are included in repository. Here is how to compute Nash Equilibrium for Rhode Island Poker with limited card deck (reduced game size )

package main

import (
	"fmt"
	"github.com/int8/go-counterfactual-regret-minimization/acting"
	"github.com/int8/go-counterfactual-regret-minimization/cards"
	"github.com/int8/go-counterfactual-regret-minimization/cfr"
	"github.com/int8/go-counterfactual-regret-minimization/games/rhodeisland"
)

func main() {
	rhodeisland.MaxRaises = 3
	playerA := &rhodeisland.Player{Id: acting.PlayerA, Actions: nil, Card: nil, Stack: 1000.}
	playerB := &rhodeisland.Player{Id: acting.PlayerB, Actions: nil, Card: nil, Stack: 1000.}
	root := rhodeisland.Root(playerA, playerB, cards.CreateLimitedDeck(cards.C10, true))
	routine := cfr.CreateComputingRoutine(root)
	ne := routine.ComputeNashEquilibriumViaCFR(10000,  8) // 10k is too small for sure 
	for infSet := range ne.Value {
		fmt.Println(rhodeisland.PrettyPrintInformationSet(infSet), ne.Value[infSet])
	}
}