jonathan@alberta.UUCP (Jonathan Schaeffer) (01/14/85)
In June of last year, I posted a message asking for
volunteers to play chess against my program, Phoenix.
Phoenix had been equipped to play correspondence chess, not
through the post office, but rather through electronic mail.
Phoenix correspondence chess (PCC) "wakes up" every night at
midnight, reads its mail, computes a response to the
opponent's move, and mails the response back to the
opponent. This process is done completely without human
intervention. It has all the advantages of postal chess,
without the cost of stamps and without the potential delays
of the postal system.
The results obtained through the use of PCC have made a
significant contribution to the development of Phoenix.
Firstly, the lack of serious games played by Phoenix has
been alleviated. In the first three months of the experi-
ment, as many serious games were played by correspondence as
were in tournaments in the preceding year. Second, after
and even during a game, the programmer can leisurely peruse
a record of the game looking for trouble spots. Once a
problem is found it can be corrected, allowing the newer
version of the program to complete the game. Certainly, one
cannot do this under tournament conditions! Thirdly, it
allows the programmer to watch his program play at a better
level than is usually possible in a tournament. In tourna-
ments, moves must be made at an average of 3 minutes per
move. When playing correspondence chess, Phoenix has been
set to use an average of 60 minutes per move. This allows
for deeper searches, and hence a "stronger" game.
The response to my initial request for opponents was
tremendous but only a limited number of games could start
due to machine availability. 16 games were started (14
humans and 2 computers) using the UNIX electronic mail
facility as the medium for communication. The original 16
games are now complete, with several new games under way.
The longest game took 3 months to finish (compare that speed
to the length of time it takes to play postal chess!), and
the shortest game, 3 moves (1. d2d4 d7d5 2. c1g5 e7e6 3.
g5d8 1:0). Phoenix has won 12, drawn 1, and lost 3 of its
games. In general, the opponents were fairly strong chess
players who took the games seriously. However, some games
had rather abrupt endings as a result of players immediately
replying to a move from Phoenix. It is easier and quicker
to reply to an electronic mail message than an ordinary
letter and this proved to be some players' undoing.
The most exciting of the games completed thus far was
against a commercially available version of Sfinks which was
allowed to compute for about 36 hours per move on average.
White's 7th and 8th move were partially the result of a bug
which was fixed immediately prior to move 9 being made!
WHITE: Phoenix BLACK: Sfinks
1. d2d4 g8f6 2. c1g5 d7d5 3. g5f6 g7f6 4. e2e3 e7e5
5. d1h5 f8b4 6. c2c3 b4d6 7. c3c4 d6b4 8. b1d2 e5d4
9. c4d5 d4e3 10. f2e3 f6f5 11. e1c1 d8d5 12. d2c4 d5c5
13. a2a3 b4a3 14. b2a3 b7b5 15. d1d4 c8e6 16. d4e4 c5e7
17. e4e6 e7e6 18. c4d2 c7c6 19. h5g5 e6d6 20. d2b1 d6c5
21. c1b2 c5e5 22. b1c3 h7h6 23. g5g3 e5g3 24. h2g3 e8e7
25. g1f3 e7f6 26. f3d4 a7a5 27. h1h5 b5b4 28. h5f5 f6g7
29. c3e4 b4a3 30. b2a3 g7f8 31. f1c4 h8h7 32. c4b3 a8a6
33. b3a4 f8g7 34. e4d6 g7g8 35. f5e5 b8d7 36. e5e8 g8g7
37. e8d8 d7f6 38. d4f5 g7g6 39. f5e7 g6h5 40. a4d1 f6g4
41. d1g4 h5g4 42. d8g8 g4h5 43. g3g4 1:0
Another of Phoenix's opponents was Belle. PCC gave
Belle "special treatment" by always searching an extra ply
deeper than in the other correspondence games (8 ply on
average). However, Ken Thompson didn't keep Belle idle.
Belle searched an average of 11 ply (including some 14 ply
searches!) and on move 24, spent an incredible 35 hours!
The game itself was a disappointment; Phoenix's first move
out of the book (move 6) is a blunder from which it could
never recover.
WHITE: Belle BLACK: Phoenix
1. d2d4 c7c5 2. d4d5 e7e5 3. e2e4 d7d6 4. f1d3 g7g6
5. b1c3 c8d7 6. f2f4 f8g7 7. g1f3 e5f4 8. c1f4 d8b6
9. d1c1 b8a6 10. f3d2 g7e5 11. d2c4 b6c7 12. e1g1 f7f6
13. a2a3 e8c8 14. f4d2 e5d4 15. g1h1 c8b8 16. c3e2 d7b5
17. d2a5 b7b6 18. a5d2 b5c4 19. d3c4 c7c8 20. e2d4 c5d4
21. c4d3 a6c5 22. b2b4 c5d3 23. c2d3 c8a6 24. f1f3 b6b5
25. c1b2 a6b6 26. d2e1 b6c7 27. e1f2 c7c3 28. f2d4 c3b2
29. d4b2 d8c8 30. b2f6 g8f6 31. f3f6 h8d8 32. f6f7 h7h5
33. a3a4 b5a4 34. g2g4 h5g4 35. a1a4 d8h8 36. a4a7 c8c1
37. h1g2 c1c2 38. g2g3 h8h2 39. f7b7 b8c8 40. b7g7 h2g2
41. g3h4 c8b8 42. a7b7 b8c8 43. b7e7 g2h2 44. h4g4 h2h8
45. e7a7 c8b8 46. g7b7 b8c8 47. b7b6 c2g2 48. g4f3 g2c2
49. b6d6 h8h3 50. f3f4 g6g5 51. f4g5 h3d3 1:0
And finally, a nice game by a mere human...
WHITE: Robison BLACK: Phoenix
1. e2e4 e7e6 2. d2d4 d7d5 3. b1c3 b8c6 4. e4e5 f8b4
5. a2a3 b4c3 6. b2c3 g8e7 7. c1g5 h7h6 8. g5h4 e8g8
9. f2f4 f7f6 10. g1f3 e7f5 11. h4f2 f6e5 12. f4e5 c8d7
13. f1d3 d7e8 14. h2h3 c6a5 15. e1g1 e8a4 16. d1e2 c7c5
17. e2d2 c5d4 18. c3d4 a8c8 19. g2g4 f5e7 20. f2h4 a5c6
21. g4g5 h6h5 22. g5g6 d8b6 23. a1b1 b6c7 24. d2g5 e7f5
25. g5h5 f5h6 26. h4g5 f8f3 27. g5h6 f3f1 28. b1f1 g7h6
29. f1f7 c6d8 30. f7c7 c8c7 31. h5h6 d8c6 32. h6f4 c7g7
33. f4f6 g7e7 34. h3h4 a7a6 35. h4h5 1:0
PCC has been a tremendous success. The only problem
has been in finding enough machine time to play a game with
everyone who wanted to play.
Jonathan Schaeffer