Okay, I finished my Zillions of Games rules file for Seirawan Chess. Now that I have that it should be brain-dead simple to make versions for Stagerlee's Super S-Chess, the the variant mentioned on the forums using Omega chess pieces. But that will have to wait until sometime when it's not almost midnight.

I found out along the way that the reason the original zrf for S-Chess was taken down was that Yasser Seirawan said there was a patent pending on the game. They are apparently trying to use IP rights to control the distribution of the game.

Anywho, I made ZoG play itself in S-Chess. I set it at highest difficulty, medium variety, and average five seconds per move. The hawks were traded off on move 10, and the elephants on move 23. From there white managed to get two passed pawns. Black sacrificed his rook to get one of them on move 62. Both sides managed to promote pawns, and both promoted to queens. I transcribed the moves from the ZoG move list (there might be errors, I saved the game if anyone has problems following this):

1. Nc3(E) Nc6
2. d4 e6
3. Nf3 Nf6(E)
4. Bf4(H) Bb4(H)
5. a3 Bxc3
6. Exc3 Nd5
7. Eb3 Hg6
8. Bd2 Qe7
9. Hd3 Hxd3
10. Exd3 Nf6
11. b4 a6
12. Bf4 Nd5
13. Qc1 Qf6
14. e4 Nxf4
15. Qxf4 Qxf4
16. Exf4 g5
17. Ed3 g4
18. Nd2 d5
19. Ec5 Ee7
20. Be2 Rg8
21. c3 Ed7
22. a4 Exc5
23. bxc5 Ke7
24. Rb1 f5
25. e5 a5
26. Bd3 h6
27. Ke2 h5
28. g3 h4
29. gxh4 Rh8
30. h3 Rxh4
31. hxg4 Rxg4
32. Rh7 Kd8
33. Ke3 Rg6
34. Rh1 Rg8
35. Rh8 Rxh8
36. Rxh8 Ke7
37. Nf3 Rb8
38. Rh7 Kd8
39. Bb5 Bd7
40. Bxc6 bxc6
41. Rh8 Be8
42. Ng5 Rb3
43. Nx36 Kd7
44. Kd3 Kxe6
45. Rxe8 Kd7
46. Rf8 Ra3
47. Rf7 Kd8
48. Rxf5 Rxa4
49. Rf8 Kd7
50. Rf7 Kd8
51. e6 Ra1
52. f4 Rg1
53. f5 Rg3
54. Kc2 Rg2
55. Kb3 Re2
56. Rd7 Kc8
57. Rg7 Re1
58. e7 Kd7
59. f6 Rb1
60. Kc2 Re1
61. Rg8 Re2
62. Kb3 Rxe7
63. Rg7 Ke6
64. Rxe7 Kxf6
65. Rxc7 Kg5
66. Rc6 Kf4
67. Rd6 Ke3
68. c6 Kd2
69. c7 a4
70. Kb4 Ke1
71. c8=Q Kd2
72. Rcd5 a3
73. Qf5 Kc1
74. Qf2 a2
75. Re5 a1=Q
76. Re1#

Would you be willing to share your rules file on the downloads section of this site?

I haven't decided whether or not to share it yet, given the patent issue. If I do share it, I'll post a link to my own site. If Seirawan wants to get legal on me, there's no sense sticking Chess.com in the middle.

Edit: After some research I decided I will release it (on my own site). Give me a few days to finish it up. I think I need to rewrite the help files, and I want to add in code for the variants I mentioned (and maybe one of my own).

Don't be too impressed, Robert. The main problem is that the zrf files have to use a very limited language (which is unfortunately not very well documented).

I tend to hold back because I don't want to clog up my castling opportunities. With all that power out there king safety seems more important. You'll notice that neither computer opponent castled. I'm wondering if that's a ZoG thing. It's a general board game AI, not a chess specific one, and I'm not sure how that affects it's chess game.

No need to hassle Mr. Harper. I think I have a pretty good idea what the legal issues are.

Okay, the Seirawan Chess rules file for Zillions of games is available on my site here. It's a 58K zip file, with the rules file and all the images needed for the game. It includes Seirawan Chess, Super Seirawan Chess (with the addition of the amazon as a drop piece), Omega Seirawan Chess (using the champion and wizard from Omega Chess instead of the hawk and elephant), and Semi-Seirawn Chess.

The last one is my version. For drop pieces it uses the knightrider (can make multiple knight moves in the same direction) and the heretic (moves as a bishop, or one square orthogonally). I liked the idea from Omega Seirawan Chess of a lower power level for the drop pieces, but I thought the pieces were too weird for the casual players I have gotten into the game. I want pieces more like the standard pieces. This also tries to fill in the weak spots for the knight and bishop: the knightrider is a knight that can move quicker, and the heretic is a bishop that can change colors.

According to the zillions web site, the AI for ZoG plays at about 1900-2000 USCF. However, all of that is tactics. It has no sense of positional play because it is not a dedicated chess engine. That may be why were seeing differences in opening strategies. Tactically, you want to bring out your powerful pieces so they can actually move. Waiting to bring them until you see how the game develops is more of a positional idea.

Anywho, the file has not been exhaustively tested, but it seems to work. Let me know if you have any problems.

Super!

By the way, I think an even better (new/modified) version of S-chess would be that game that uses a random # generator to select the drop pieces.

candidate pieces:   

Hawk

Elephant

champion (from Omega Chess)

the Bear (from Bear Chess)(also known as the Super Knight)

wizard (from Omega Chess)

Royal Rook (from Rutledge Chess)

There are 15 different sets-of-2 that can be selected from this group of 6 drop pieces.  So each game will very likely have a slightly different army than the one before it.

To RAB:       those 15 (slightly) different armies go even further to assure that people don't have too extensive opening books

And -- for those who like the drop chess concept, but feel the H & E dwarf the minor pieces, they can select the Champion and Wizard, both of whom are less dominant than the Rook. 

I believe ZoG is a Windows only program. You would need an emulator.

An emulator is a software program that simulates one system on another system. For example, I can get an emulator that simulates the old Nintendo Entertainment System on my Droid cell phone. What you would need is an emulator that simulates Windows on your Macintosh. I'm not familiar with the specific emulators that are available these days. I haven't owned a Mac since the 90s.