Author: Andreas Stabel
Date: 06:30:11 06/08/99
I'm not the worlds best chess player (ANST rated 1200-1300 on FICS), but I
thought I knew something at least.
Now I'm in serious doubt. As a professional computer programmer I of course
couldn't keep my hands off trying to make a chess playing program. I don't
have much time for this, so I've been on and off for many years.
Now finally I've at least managed to make a program which can do the
following: Play all legal chess moves, knows of mates and
stalemates and has a simple evaluating function which just calculates
material and says that a pawn is better the more advanced it is. THAT'S ALL !
The search algortithm is also very simple. I think it is some sort of
alpha-beta though I seem to only have an alpha :)
I have no hash table, no opening book, no endgame table bases, no learning,
a simple quiecense search and an even simpler move ordering which takes winning
captures first (where the hitting piece is of less value than the one captured)
and then the other moves in the sequence they are generated.
After finding a lot of bugs and misunderstandings, I now have got the
program working. I have played test games against it all the time to see
if it did what I expected it to do, but it has been very easy to win.
But now everything has changed. I have LOST the two last games I played
against it !!! (see PGN at the end)
This shouldn't be possible. The program plays like an idiot. It just
pushes pawns whenever possible and messes up it's king safety and the
positions looks terrible for the machine but still it WINS :(
Of course I haven't played on its weakness. I could have played safely,
just slowly exploiting the bad position and protecting my pieces, but I've
never liked playing this way. I love attacking and trying crazy (and mostly
loosing) combinations and this has of course backfired.
But the big point here is that the program knows so little and gets into
so bad positions that I thought I would win easily anyway. This has turned out
not to be true. The program ususally only sees 3-4 plies before the
quiecense search, but this is more than enough to find winning tactics
against me as the two games clearly show. It seems that the ability to look
deeper than what I do enables the program to escape the messy posisitons it
gets into and as soon as I overlook something it jumps on me. All my chess
knowlegde beaten by a couple of plies. I'm depressed :(
My only consolation is that when I analyse the game using crafty, most of
my moves look reasonable and the score stays at about even or + for me most
of the time - untill the tactics turn against me.
There is of course another way of looking at this. To imagine that the
best chess players in the world beat the most powerful computers with big
opening books, learning, endgame table bases and as much chess understanding
as Mr. Hyatt and the rest has been able to put into them through decades.
This is very impressive and tells us how powerful the human brain is.
Pity my brain isn't that impressive :)
I think I finally have gotten a practical proof of the distance between
these masters and me.
If there are somebody else who have experienced similar setbacks I hope
this report can show that you are not alone.
Where to go from here ? Tic tac toe perhaps :)
P.S. Here are the games in PGN:
[Event "Test of move program"]
[Site "ANST PC"]
[Date "1999.06.07"]
[Round "-"]
[White "Move"]
[Black "ANST"]
[Result "1-0"]
1. h4 d5 2. f4 Nf6 3. d4 b6 4. b4 e6 5. c3 c5 6. Qa4+ Bd7 7. b5 a6 8. e3
Qc8 9. h5 Qb7 10. dxc5 axb5 11. c6 Qxc6 12. Qd1 Na6 13. g4 Ne4 14. Qc2 Rc8
15. a4 bxa4 16. Bxa6 Rc7 17. Bb2 Bb4 18. Ne2 b5 19. Qd3 Nc5 20. Qxb5 Nxa6
21. Qxc6 Rxc6 22. cxb4 Nxb4 23. Rxa4 Nc2+ 24. Kd2 O-O 25. Ra7 Rd8 26. Bc3
Nxe3 27. Kxe3 Bc8 28. g5 Rcd6 29. Be5 Rc6 30. Rc1 Rb6 31. Ra8 Rb3+ 32. Kf2
Rxb1 33. Rcxc8 f6 34. Rxd8+ Kf7 35. Rd7#
1-0
[Event "Test of move program"]
[Site "ANST PC"]
[Date "1999.06.08"]
[Round "-"]
[White "ANST"]
[Black "Move"]
[Result "0-1"]
1. e4 d5 2. e5 h5 3. d4 f5 4. b3 a5 5. c4 e6 6. Nf3 Bb4+ 7. Nbd2 Bc3 8. Rb1
dxc4 9. bxc4 Bxd4 10. Qa4+ Bd7 11. Qb3 Bb6 12. c5 Bxc5 13. Qxb7 Nc6 14. Bb5
Ra7 15. Bxc6 Rxb7 16. Bxb7 a4 17. O-O g5 18. Nc4 g4 19. Bg5 Qb8 20. Nh4 a3
21. Rfd1 Qa7 22. Rd2 Qa4 23. Ne3 f4 24. Nc2 Qc4 25. Rbd1 Ba4 26. Rd8+ Kf7
27. Rc8 Qxc2 28. Rxc7+ Ne7 29. Rf1 Bxf2+ 30. Rxf2 Qxc7 31. Ba6 Qxe5 32.
Bxe7 Qa5 33. Bxa3 Qxa6 34. Rxf4+ Ke8 35. Ng6 Qb6+ 36. Kf1 Qb1+ 37. Kf2 Qxg6
38. Rxa4 Qc2+ 39. Kg3 h4+ 40. Kxg4 Qf5#
{Black mates} 0-1
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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