Monday, February 28, 2005

Suicidal Cake

My suicide checkers program, Suicidal Cake, has reached version number 1.08. It has a 6-piece endgame database, I suppose I am the first to compute this database. It also has an opening book of about 36'000 moves right now, with approximately 2000 more added each day. Suicide checkers is extremely tactical, many lines in the book have more star moves than non-star moves. This makes the game very hard for humans. It's hard for the programs too of course, as one mistake might cost you the game! Suicidal Cake has the huge advantage of an endgame database, which is more important in suicide checkers than in regular checkers; I'll return to this later. Suicidal Cake has played some games against two of the world's best suicide players, and has won every single game. I believe it is the strongest suicide checkers playing "entity" on the planet right now. Here's a game where the endgame database played a part, you can copy and paste the game into CheckerBoard.

[Event "Email game"]
[Date "2005-02-20"]
[Black "N.N."]
[White "Suicidal Cake 1.08"]
[Result "0-1"]
1. 11-15 24-19 2. 15x24 27x20 3. 8-11 21-17 4. 11-15 17-13 5. 12-16 20x11 6. 7x16 22-18 7. 15x22 26x17 8. 16-20 25-22 9. 4-8 28-24 10. 20x27 31x24 11. 8-11 29-25 12. 3-8 23-18 13. 10-14 17x10 14. 6x15 13x6 15. 1x10 30-26 16. 15-19 24x6 17. 2x9 18-14 {Suicidal Cake returns the man it has won to reach a winning 2 vs 2 endgame database position} 18. 9x18 22x15 19. 11x18 26-23 20. 18x27 32x23 {And here it is, this position is a win for white. Would you have guessed?} 21. 5-9 23-18 22. 9-13 18-15 23. 8-12 25-21 24. 12-16 15-11 {Red resigned. Play might have continued:}
25. 16-19 11-8 26. 19-23 8-4 27. 23-27 4-8 28. 27-32 8-11 29. 32-27 11-15 30. 27-32 21-17 31. 13x22 15-19 32. 22-25 19-23 33. 32-28 23-18 34. 28-24 18-22 35. 24-19 22x29 36. 19-24 29-25 37. 24-19 25-22 38. 19-16 22-18 39. 16-20 18-23 40. 20-24 23-27 41. 24x31 0-1

2 comments:

George Miller said...

Or after 30. 27-32 15-18 31. 32-28 18-23 32. 13-17 0-1 - not as pretty as Cake, but easier to find! Those databases look hot...

Ed Gilbert said...

Hi Martin,

Nice job with the suicidal cake. When I first heard about this game I thought maybe I could simply change the comparison in alphabeta to make the engine play this variation, but on more thought and reading your posts I realize there is much more to it than that.

I've been corresponding with the programmer of 'Tundra', which plays English/American, Russian, and suicide checkers. He has an 8pc database for all those versions, but I'm not sure if his suicide checkers plays the English style. You might want to try your program against his. Tundra has a web site, but its all in Russian. I'll send you his email address if you're interested.

-- Ed