Milhouse needs an opening book…

I decided to play a game against Chinook set on its intermediate level. It was lost before it even began. Fortman’s Basic Checkers lists 3. 16-19 … as the only viable move for Black, and the convincing way that Chinook took me apart is a pretty good ilustration that even with an 18 ply search, Milhouse was unable to extricate itself from that move. I think I need an opening book.

[Event "Sparring Match"]
[Date "2009-04-27"]
[Black "Milhouse"]
[White "Chinook (Intermediate)"]
[Site "Internet"]
[Result "0-1"]
1. 10-14 22-18 2. 12-16 24-20 3. 7-10 28-24
4. 8-12 24-19 5. 3-7 25-22 6. 9-13 18x9
7. 5x14 22-17 8. 13x22 26x17 9. 1-5 29-25
10. 14-18 23x14 11. 16x23 27x18 12. 10-15 25-22
13. 15-19 17-13 14. 11-15 18x11 15. 7x16 20x11
16. 6-9 13x6 17. 2x25 21-17 18. 25-29 17-14
19. 12-16 11-7 20. 16-20 7-3 21. 19-23 3-7
22. 20-24 7-10 23. 5-9 14x5 24. 4-8 10-15
25. 23-27 32x23 26. 24-28 15-11 0-1
After 3. 7-10... White to move and win...
After 3. 7-10... White to move and win...

Addendum: With a 20 ply search, you can see that Milhouse thinks that 6-10, 7-10, and 8-12 are all more viable. Broken.

            -9 :  6-10 25-22  8-12 28-24 10-15 22-17 15x22 17x10  7x14 26x10  2-7  10-6   1x10 23-18
            -9 :  7-10 27-24  8-12 24-19 10-15 19x10  6x22 25x18  3-7  28-24  7-10 30-25  4-8  24-19
            -9 :  8-12 28-24  7-10 24-19 10-15 19x10  6x22 25x18  3-7  27-24  7-10 30-25  4-8  24-19
          -109 :  9-13 18x9   5x14 23-18 14x23 26x12  7-10 27-23  6-9  25-22  2-6  30-25 10-15 21-17
          -111 : 11-15 18x11  8x15 20x11  7x16 23-18 15x22 25x18 14x23 26x12  2-7  27-23  6-10 23-18
          -116 : 14-17 21x14 11-15 18x11  8x15 20x11  7x16 23-19  9x18 19x10  6x15 26-23  2-6  23x14
           -97 : 16-19 23x16 14x23 26x19  6-10 25-22 11-15

Well, not really broken. Playing 3. 16-19 requires Black to play a man down for the duration of any reasonable search horizon. Mihouse will have difficulty playing into man down openings because of its relatively weak evaluation function. It will absolutely require an opening book to survive openings like this one.

Addendum: Things to do: try to see if Milhouse does better if the roles were reversed in this position. I also have been pondering coding up some form of opening book generator based upon Lincke’s “drop out expansion” idea. It’s actually pretty straightforward, and I could leverage a couple of multicore desktop machines to probably create a basic opening book in a month or two of runtime. Or, I could just try to make use of Martin Fierz’s book in Cake. But that would be cheating. Sort of. 🙂

Milhouse defeats Chinook (on amateur level anyway)

Oddly Chinook seemed to know the end was coming before Milhouse recognized it. But sure enough, Milhouse managed to navigate itself to a victory.

[Event "Sparring Match"]
[Date "2009-04-27"]
[Black "Milhouse"]
[White "Chinook (Amateur)"]
[Site "Internet"]
[Result "1-0"]
1. 12-16 22-17 2. 16-19 24x15 3. 11x18 23x14
4. 9x18 28-24 5. 8-11 26-23 6. 6-9 23x14
7. 9x18 24-19 8. 2-6 17-14 9. 10x17 21x14
10. 4-8 31-26 11. 11-15 19x10 12. 6x15 25-21 
13. 8-11 29-25 14. 1-6 26-22 15. 6-9 21-17
16. 9-13 27-23 17. 18x27 32x23 18. 15-19 23x16
19. 11x20 30-26 20. 20-24 25-21 21. 7-10 14x7
22. 3x10 26-23 23. 24-27 23-19 24. 27-31 19-16
25. 31-26 16-11 26. 10-15 11-8 27. 26-23 8-3
28. 23-18 3-8 29. 18x25 17-14 30. 25-22 14-10
31. 22-18 8-11 32. 15-19 10-7 33. 13-17 21x14
34. 18x9 11-15 35. 19-23 7-2 36. 23-26 15-10
1-0

Sparring Milhouse versus Chinook

Well, I’ve mucked around a bit, and begun to add PDN (Portable Draughts Notation) logging to Milhouse. Here is a sparring match between the novice version of Chinook that you can play online versus Milhouse, running at around 15 ply search with a six piece endgame database. It seemed clear that the position was a draw at the end. Chinook seemed to think I had it on the ropes around move 19. Did milhouse miss a strong line, or is the novice level of Chinook misguided? I’m not sure.

[Event "Sparring Match"]
[Date "2009-04-27"]
[Black "Milhouse"]
[White "Chinook (Novice)"]
[Site "Internet"]
[Result "1/2-1/2"]
1. 11-15 22-18 2. 15x22 25x18 3. 8-11 29-25 4. 4-8 24-20 5. 12-16 26-22
6. 8-12 28-24 7. 9-13 30-26 8. 10-15 24-19 9. 15x24 18-15
10. 11x18 20x11 11. 7x16 27x11 12. 18x27 31x24 13. 12-16 32-27 14. 6-10 24-20
15. 10-15 11-8 16. 3x12 20x11 17. 12-16 11-8 18. 15-19 21-17
19. 16-20 27-23 20. 19-24 23-19 21. 24-27 19-16 22. 27-32 17-14
23. 20-24 8-4 24. 24-27 25-21 25. 1-6 16-11 26. 13-17 22x13
27. 6-9 13x6 28. 2x18 26-23 29. 18-22 21-17 30. 22-25 17-14
31. 27-31 23-19 32. 31-26 19-16 33. 25-29 14-10 1/2-1/2