go-fathom

Syzygy tablebase probe implementation for Go.

This package wraps a fork of an original Fathom tool written in C: https://github.com/jdart1/Fathom.

Also it uses well-known external package https://github.com/notnil/chess as a public communication layer.

Interface methods allow to probe DTZ and WDL tables (*.rtbw and *.rtbz Syzygy tablebases).

Tablebase files

If you don't have tablebase files yet, follow this link and explore suggested TXT. These TXT files contain URLs to tablebase files you should download.

Example: play chess.Game

We are going to call fathom.ProbeRoot(...) and apply the suggested move in a loop until the game is over.

package main

import (
	"fmt"

	gofathom "github.com/bbars/go-fathom"
	"github.com/notnil/chess"
)

func main() {
	fen := "4k3/7q/8/8/8/8/B61/4K3 b - - 0 1"
	
	fathom, err := gofathom.NewFathom("./path/to/tables/chess/")
	if err != nil {
		panic(err)
	}
	
	fenOption, err := chess.FEN(fen)
	if err != nil {
		panic(err)
	}
	game := chess.NewGame(fenOption)
	game.AddTagPair("FEN", fen)
	fmt.Printf("FEN: %q\n\n", game.Position())
	
	// generate moves until game is over
	for game.Outcome() == chess.NoOutcome {
		tbMove, _, err := fathom.ProbeRoot(game.Position())
		if err != nil {
			panic(err)
		}
		// select a best move
		move := tbMove.Move()
		fmt.Printf("%s move %s -> ", game.Position().Turn(), &move)
		err = game.Move(&move)
		if err != nil {
			panic(err)
		}
		fmt.Printf("%s\n", game.Position())
	}
	// print outcome and game PGN
	fmt.Println(game.Position().Board().Draw())
	fmt.Printf("Game completed. %s by %s.\n\n", game.Outcome(), game.Method())
	fmt.Println("PGN:\n")
	fmt.Println(game.String())
}

Example: call all available funcs

Here we are going to invoke all available funcs to analyze the state.

package main

import (
	"fmt"

	gofathom "github.com/bbars/go-fathom"
	"github.com/notnil/chess"
)

func main() {
	fen := "4k3/7q/8/8/8/8/B61/4K3 b - - 0 1"
	
	fathom, err := gofathom.NewFathom("./path/to/tables/chess/")
	if err != nil {
		panic(err)
	}
	
	pos := &chess.Position{}
	err = pos.UnmarshalText([]byte(fen))
	if err != nil {
		panic(err)
	}
	
	fmt.Println("# fathom.ProbeWDL")
	res1, _ := fathom.ProbeWDL(pos)
	fmt.Printf("%#v = %s\n", res1, res1)
	
	fmt.Println("\n# fathom.ProbeRoot")
	tbMove, res2, _ := fathom.ProbeRoot(pos)
	move := tbMove.Move()
	fmt.Printf("move: %#v\tstring: %q\n", move, &move)
	fmt.Println("move#\tWDL\tDTZ")
	for _, tbRes := range res2 {
		move := tbRes.Move()
		fmt.Printf("%s\t%s\t%v\n", move.String(), tbRes.WDL(), tbRes.DTZ())
	}
	
	fmt.Println("\n# fathom.ProbeRootDTZ")
	res3, _ := fathom.ProbeRootDTZ(pos, true)
	fmt.Println("move#\tRank\tScore\tPV")
	for _, tbRes := range res3 {
		move := tbRes.Move()
		fmt.Printf("%s\t%v\t%v\t%v\n", move.String(), tbRes.Rank(), tbRes.Score(), tbRes.PV())
	}
	
	fmt.Println("\n# fathom.ProbeRootWDL")
	fmt.Println("move#\tRank\tScore\tPV")
	res4, _ := fathom.ProbeRootWDL(pos, true)
	for _, tbRes := range res4 {
		move := tbRes.Move()
		fmt.Printf("%s\t%v\t%v\t%v\n", move.String(), tbRes.Rank(), tbRes.Score(), tbRes.PV())
	}
}