Comments/Ratings for a Single Item

Roberto:  I have found a couple of bugs in the function that decides when
the King is in check (the problem responsible for the Kings being
captured.)  I will e-mail you a new program file shortly ...  There could
still be additional bugs with this, though ...  Check-detection in Ultima
is *really* ugly!  But when these problems are solved, I bet it will
immediately play a much smarter game.

Fergus:  Ick!  I have heard a similar report from a Windows 98 user.  I
assume you are using Windows 95/98/ME ...  Which is not to say that the
problem is with your OS, and not with my program; it's just that this
problem is extra-tricky for me to solve...  The new versions of Microsoft
Developer Studio do not run on Win 95/98/ME at all, which means that I
cannot use the debugger to help me track this problem.  Still, I need to
come up with some way to find and fix this.  And, if you are running
Windows 2000/XP, then my problems are even worse than I thought :)

Yes, I did an mental exercise and I think you are right about the
difficulties to write the code about when the King is in Check. One
possible solution is changing the objective of the game to the
capture-the-King rule, as in Zillions.
Chess V is a relatively good player in open positions, because the program
can calculate many tactical moves, it is not easy for a human do it in a
good manner in this game, due the great mobility of pieces and
combinations. The program is less abile in closed positions, because it
does not understand well positional concepts, in fact, it is not designed
using positional evaluation functions, but I agree with Greg, the program
should be smarter if the Check condition detection is well solved, because
part of the responsability of the bad play in some instances is the
incorrect evaluation of the King vulnerability.

With the help of my son and a friend, we finished the fever caused by the
fifth test game with a victory over Chess V after 6 titanic hours of a
very disputed game to complete near 85 moves (we played White, and Chess V
used 10 sec. per move in Pentium IV, 2.1 GHz.). The program played really
well, it attacked and defended strongly, but this game is very
instructive, it puts on the carpet the way of taking positional advantages
in this kind of closed positions, and shows why this is a game which
sometimes favours defense over attack. See and enjoy it!:

Ultima
f2f4 g7g5 e1g3 a7a4 h2h5 b7b5 g3g4 c7c4 g1h2 h8c3
 e2e3 d7a7 g4g3 d8d4 e3f3 f7f6 h2g1 d4e4 !c2 e4g6
 c1c2 g6f7 d1c1 h7h3 g1h2 g8h8 g3h4 c8g4 h4h7 f8h6
 h2g3 g4h3 g3h2 h6h4 f4e4 f7d5 h1g1 d5b7 g1e3 h3h1
 e3d4 b8g3 f1d1 g3e3 d4b4 h4d4 a2a3 e8d8 b4b3 h1h4
 g2g1 h8g7 b2a2 b7d5 c2c3 e3e6 a1b2 d5g2 c3g3 g7g8
 b1c2 d4d6 g3g7 g8g3 d1f1 e6e5 a2a1 a8g2 c2h2 h4h1
 b2h2 a4h4 f1h3 e5c3 c1d1 d6d5 d1e1 f6h6 e1f1 d8c8
 f1g2 d5f3 g2h1 h4f4 b3d1 h6e6 d1f1 e6e4 h2g2 f4h4
 h1h2 c3e5 g1h1 b5b4 h2g1 e4e2 g1f2 e5f4 h1h2 f4e4
 f2g3 e2f2 g3f2 e4b1 f1d3 b1g6 g2a8 c8d8 h3e3 g6h6
 e3e5 h4f4 h2h1 h6a6 f2f3 a6a5 e5g7 a5a2 f3g4 f4e4
 g4h5 e7d7 h5g6 d7d6 g7f8 e4f4 g6f6 a2e6 f6g7 e6a2
 g7g8 a2a3 f8f7 a3a2 a8b7 d6d7 b7c6 b4c4 g8f8 c4b4
 f7e8 d8c8 c6b6 c8b8 e8d8 a2c2 f8e8 d7d5 e8d7 f4f8
 d7e8 f8f3 b6b5 d5c5 b5d3 f3f4 d3b3 f4e4 a1a5 c5d5
 d8b6 d5d1 e8d7 b8a8 d7c7 a7b7 a5a7 !c2 b6b7

Greg, I tried to load the 5th. test ULTIMA game, saved file, and I found an
illegal move saved (the saved game couldn´t be loaded, by this reason),
number 9, it shows !c2, and the same move is saved as the last move of the
game. You can see it in the list of moves I sent as a comment on the game,
or I can send you the saved file, as you prefer. I don´t remeber what move
I made as 9th., but it was surely legal, and I can´t understand what !c2
means. 
As for the program, I finished the 6th. test game yesterday night, and I
Chess V won. It is now strong enough, I think, I used the 'take-back'
facility a lot of times, but the program beated me playing with great
force. Would you tell me what changes have you made in the program?.
Excellent improvements!

Yes, I see the bug you mention.  The move !c2 is a suicide move
(immobilized piece on c2 kills itself.)  Apparently, it is not reading the
sucide moves back in correctly.  I will post a fix shortly.  

About your question, what changes I made ...  I fixed several bugs ... Not
just the check-testing bug, which allowed the King to get captured, but I
also found a couple of others where things were not being evaluated
correctly.  The program now functions (hopefully) exactly acording to the
evaluation function previously described.  In other words, the bad play
you experienced was entirely caused by bugs.

Thank you for testing, and reporting these problems!
Greg

Good job! I used ChessV to produce nice pictures for Wikipedia article on
Capablanca Chess, see http://en.wikipedia.org/wiki/Capablanca_Chess.

Wish List:
* Would be nice if settings made in 'Options / Board and Pieces...'
would be kept between program starts.
* I use 800x600 screen resolution and games with 10x10 board, e.g. Grand
Chess doesn't fit on my screen. Would be nice if the board is scaled
automatically when window size changes, like in Arena.
* Pieces are flashing when you make a move. This can be fixed e.g. by
using double-buffering technique.
* Can we have Three Checks Chess in ChessV (see
http://en.wikipedia.org/wiki/Three_Checks_Chess)? Zillions plays it quite
pure.

Thank you for development of this nice program!

Yes, now I noticed that color settings are stored per specific game type. I
think, it would be nice to have possibility to apply the color changes to
all game types (may be with an option to apply only to one game type as
now). By the way are there any reason to restrict the number of available
colors to 48? With more available colors it is easier to find a nicer
color scheme.

I also found a bug in Bird's Chess. ChessV castled out-of-check in
position after:

d2d4 f7f6 i1h3 g7g5 g2g3 g5g4 h3i1 h8g7 f2f3 i8h6 f3g4 h6g4 h1f3 e8g6 i1h3
d7d6 e2e4 c8d7 e1e2 e7e5 d4d5 f6f5 b1c3 h7h6 h3f2 g8j5 f3g2 j5i6 f2g4 i6g4
g2f3 g4f6 c1d2 g6f7 d1f2 j8g8 f1c1 f5e4 f3e4 j7j5 h2h3 b8a6 g1j4 a6c5 e4g2
i7i5 j4i3 f6i3 f2f7 d8f7 j2i3 g7f6 j1j5 g8g3 d1f1 c7c6 j5j8

ChessV played 0-0-0 here, despite King being in check by rook on j8.

There is no good reason for limiting the colors; I just haven't gotten
around to adding the color-picker dialog yet.

There are several reasons why it would be problematic to make global piece
& color settings.  For one thing, not all piece sets are supported by all
games.  Right now only the Standard set supports all, but the Abstract set
is pretty close.  Also, although right now all boards are 2-colors, the
boards for some games will be 3 or 4 colors.  Finally, I wanted to be able
to provide default settings for games, like Chaturanga, for example, always
appears for the first time on an uncheckered board with the Old World
pieces.  If you could provide global settings, then it wouldn't appear
right by default - it would have checkered squares.

Thanks for the bug report!  Someone had reported this on sourceforge, but
didn't provide me with an example, so I couldn't reproduce it.  Now it
should be easy to track down ...

Excellent program!  Please do not keep it a secret.  Share it with the
world by making it available thru more than one hot spot.  I certainly am
not criticizing 'Source Forge' but the most popular download spot in
the
world for games by far is:

WinSite
http://www.winsite.com/

Establish an account and upload to the 'Fun & Games' category, 'Chess
Games' sub-category.

I predict that a free, fully-functional, incisive AI program (with a good
selection of games) like yours will soon draw thousands of downloads.

Rest assured, this is NOT spam- just a well-intentioned recommendation.

Threaded MS Windows operating systems are the problem, not your program.

Whereas NT versions of MS Windows have been the default offerring for
consumers since 2000, I think you are being overly-conscientious in this
case.  If someone complains about ChessV's installation or performance
under MS Win 95, for instance, just tell them to get a decent, modern
operating system.

Yes, it is a great software, I have tried it. To Gregory Topov: Chess V
runs well in Windows XP, but it has some troubles under other Windows
versions. The author (named Greg too) gives us this adress to download the
program:
http://sourceforge.net/projects/chessv

When Chess V evaluates positions that are materially equal, how does it
choose between them?  That's more than just a rhetorical question.  We
know there are bound to be thousands of positions that are strategically
and tactically a dead draw.  Whatever distinctions can be found, they
must
be very subtle.  For instance, at the start of the game, what makes 1.
Pa2-a6 any better than 1. Pa2-a3?  Does Chess V employ at some point a
random function to choose between the moves available to it?  If Chess V
plays against itself, how does it perform if the only thing different is
the random seed?  Does C as a programming language allow use of different
pseudo-random number generators, or are you stuck with the one that comes
with your C package?  Would two different versions of Chess V perform
differently if the only thing distinguishing them were the random seeds
inside the C source code?

As for numerical values representing the strengths of the pieces, were
the
figures arrived at through empirical analysis, or by guessing?  Empirical
analysis implies that different versions of Chess V performed differently
when pitted against itself, and the data produced was relied on for newer
versions.

In terms of Ultima/Baroque, any group of 3 or more same-colored pawns
situated, together, a single knight's move away from each other, make
for
a much stronger structure than those that are not.  This may mean more to
us in an endgame than from the typical starting position, so it should be
examined after the variables for fluidity/mobility are arrived at. 
Although a pawn or pincher can strike against enemies bounded by
non-enemy
pieces, the relative slowness of a group of pawns (compared to a group of
noble piece) means that 'pawn structure' - as such - can be a fruitful
thing to look for.  In terms of endgame analysis, it may take 1 king + 5
pawns to force checkmate - I'm not sure - but I don't think mating is
possible with just 3.

The peculiar thing about this, is how the knight's move of traditional
chess finds a place for evaluating pawn structures in Ultima/Baroque.  It
relates to the desirability of distributing same-colored pawns equally
across a finite area of rectangularly gridded space.

The setting of I-Depth 9 is just the maximum depth.  The way it works is
that it searches all moves to a depth of 1, and then, if there's time, to
a depth of 2, and, if time, to a depth of 3, etc...  So it never hurts to
have the Max I-Depth set high.  The only reason that setting is there is
so that, if you want to do a fixed-depth search, you can set the I-Depth
to the depth you want, and set the time limit to something really high. 
And, strangely enough, searching to a depth of 1, then 2, 3, ..., n is
actually faster than going straight to depth n.  This technique is called
'Iterative Deepening', and is used by all chess programs.

Giving pincer pawns a bonus for being a knights-move away from others
might be a good idea.  I might give it a try sometime and see how it
works.

I just read through some of the comments on here about ChessV and Gothic
Chess. Some were not 100% on the mark. First of all, ChessV was given a
one-year Gothic Chess license from November 2004 to November 2005. ChessV
played in the first, bi-annual Gothic Chess Computer World Championship.
You can read more about this on chessville here:

http://www.chessville.com/GothicChess/ComputerWorldChampionships.htm

There was also some discussion about the graphic which was displayed by
the ChessV engine. Greg is confusing two issues. I did contact him about
something regarding Gothic Chess, but it it was not the item he mentioned.
After his license expires and is not renewed, the subsequent versions of
ChessV could not contain a Gothic Chess setup, and that is all.

I also contacted somebody about an image shown on Wikkepedia under Gothic
Chess. It was ORIGINALLY one I had drawn and is widely in use. The one
that replaced it was a ChessV board's image of Gothic Chess.

Again, I believe the sands of time have led to Greg confusing issues. I
never said what was represented by him or others.

I've already got a handful of those 256 meg thumb-drives, too, and I love
the direction technology is taking them.  Flashram is the wave of the
future.  Unfortunately, I have had more than my share of bad luck with
Intel systems, and the rate at which my last few PC compatibles crashed
makes me view the benchmarks and forecasts they've come up with, with
suspicion.  (It is rumored that thumbdrives rarely last more than a year
from the time you first buy them, and put them to use, hot swaps and
all.)
 Nobody is forcing you to boot up an ST emulator just to try out my code,
just bear in mind that not everybody has a computer that you consider
state of the art.

As for generating a mini-max tree, how deep should you go before you
start
pruning?  I know you recommend a 9 ply search (just under 5 full moves),
and I have nothing against that.  In an endgame consisting of four or
five
pieces, it sounds perfectly reasonable to do a 30 or 40 ply search - the
space required is far less than at start, you just have to look into the
possibility that you are revisiting a board that you've already
generated
somewhere higher up (earlier) in the tree - maybe with the tempos swapped
-
but you can save a ton of space that way.

Say, from the sample Ultima games here at www.chessvariants.org, I
wasn't
entirely sure why the players were holding back and playing 1. Pg2-g4 or
1.
Pf2-f4 (recounting from memory, I may be wrong, they were only seizing a
couple of squares of territory) instead of pushing the pawns up to the
limit possible, like 1. Pf2-f6 or 1. Pg2-g6 and let them bite the dust if
that's what it's cracked up to be.  As principles go, is it really that
dangerous to hog space - even throw pawns away - for the sake of reaching
a game that is that much more open?  In any case, whether the Leaper is
capable of single or multi-leaps, losing a Leaper is going to be the most
momentous occasion in the game.

Version 0.81 Released

An important update, this has several bug-fixes and performance enhancements to correct problems reported in version 0.8. This version should be significantly smarter about how it plays.

This version also adds support for Fergus Duniho's Eurasian Chess. NOTE: this is by far the most computing-intensive game added yet, not just because of the number of pieces, but more importantly because of the cannon-movers. With cannon-movers on the board, it is much harder to determine which captures are winning captures, and thus many, many more moves must be examined in the quiescent-search. Any less than 10-15 seconds per move and it is not likely to play very well.

Download from sourceforge.net here

Version 0.9 Released

For those who don't know, ChessV is a freeware, open-source program for playing Chess variants. It has been over a year since the last release, and this is a major upgrade. This version has support for over 50 variants, and allows users to add in their own variants! Of course, it also fixes numerous bugs.

New games: Support added for Great Shatranj, Odin's Rune Chess, Chess 480, Cagilostro's Chess, Embassy Chess, Emperor's Game, Janus Kamil Chess, Ladorean Chess, Univers Chess, Schoolbook Chess, Modern Kamil, Roman Chess, Royal Court, and Shatranj Kamil.

New features: It is now possible to design your own variants (within limits.) This ability is different that that of Zillions, however, in that you don't program an entire game from scratch. Rather, you derive your game from one of the built-in games, and specify only how it differs. This makes it fairly easy to add support for new games, but it is limited. It is not anywhere near as flexible as Zillions. On the upside, however, ChessV will play any game that it allows you to make with a very high level of skill. See the file extensability.doc for info on how to add new variants. Other new features include the ability to use textures for squares instead of only solid colors. Several marble textures are included.

Download: Download this program from the project's home on sourceforge.net here. You only need to download the main file (ChessV_0_9.zip), not the source code unless it interests you. There is no setup program - just unzip and run. If you have an old version of ChessV already, just unzip this on top of the existing versions.

Please report any bugs you encounter. You may post them here, or email them to me (you can get my e-mail from the chessvariants.org member's index.)

If you're interested, I can help by having a command-line version that can compile uisng the standard Gnu/UNIX toolchain--it would be nice to compile this program on something besides Windows + MSVC. I think that would encourage more developers (I'm a Linux developer who makes Windows ports with MingW32).

Again, thanks for the great work Greg. Good to see you back--I missed you!

- Sam

Thanks, Sam.  ChessV, thankfully, is not dead.  It had just been so long
since the last release, that I wanted to take the time to make sure that
the next release was a major step forward.  Yeah, the 0.8x versions had a
nasty bug that resulted is the occasional really bad move.  That has been
fixed, along with a dozen or so other miscellaneous bugs.

In addition to supporting the rules for Schoolbook, if you look in the
openings directory, you will see a small opening book.  Although it only
has a few lines of play in it, each move was calculated extremely deeply
using several very powerful computers I have at work.  A few days worth of
CPU time went into it, although, that being said, it is just a start ... 
(In addition to Schoolbook, a similar effort has gone into making opening
books for other 10x8 variants, primarily Grotesque, Ladorean, and
Univers.)

A note about opening books:  The opening books are just text files, and
while the format should be pretty self-explanatory, it occurs to me that
there is one thing that hasn't been documented and is worth noting.  Some
moves in the opening books are preceeded with a question-mark.  The
question-mark denotes an inferior move, and the computer will not make
that move.  The point of including it is so that if the human makes that
move, the computer will know the correct response.

Regarding porting to other operating systems:  I am very interested in
seeing ChessV ported to other platforms, primarily Linux.  This has always
interested me, but I have very little knowledge about other platforms. 
Still, I made a few design decisions specifically for the purpose of
making such a port easier.  For one thing, I did not use Microsoft
Foundation Classes, or any other Windows-centric class library.  ChessV
uses only standard Win32 calls, and I called as few different functions as
possible.  Sound, animation, and other bells-and-wistles were deliberately
left out to make the code more portable.  Also, all calls to Windows
functions are preceeded with :: (which is unnecessary because these
functions are global anyway, but I did it so that if you someone searches
for ' ::' it will turn up all calls to Windows functions in one shot.) 
Finally, I wrote some classes to be a thin wrapper encapsulating some of
the Windows graphics objects, like pens and brushes, so that the code
would only need to be modified in one place, but I must admit that I
didn't do nearly as much of this as I would like.
So, yes, I would be happy for any help you could provide to make ChessV
more portable.  I do not know much (if anything) about MingW32, though... 
Does it only allow one to port console applications, or does it emulate
some of the GUI functions as well?

Thanks again for the positive feedback!
Greg

Excellent! I've enjoyed playing this; that it plays opening pawn moves
alone puts it ahead of Zillions. The only part I don't like is that it
keeps beating me. Great to see this out. Thanks. Joe
ps: love the shatranj section!

There should be a subdirectory called 'images' and then subdirectories
under that for the different piece sets.

Ok, I checked that and that's right. the images are in subds under
images, they're not out in the main directory.

maybe i still don't get it.  is there something else that i can try and
fix?

Yes when I unzipped it, the same thing happened to me, all the image files
were being replaced, then nothing came up when I launched the program.
Here is what to do to fix it. 

1. Double click the chessV.zip file.
2. If using Winzip, you have to hit the 'extract' button.
3. This brings up a window asking you where you want the files to go.
Make
sure you check the 'Use folder names' box on the bottom right! 

It seems to me this shouldn't even be an option it should always do
this.

Anyway that will extract ChessV files into all the right places.

Winzip has a way of destroying all of the subfolders that a .zip file has; this will break ChessV. The solution is simple: Don't use Winzip. WinXP's .zip extractor is simpler, better, and cheaper.

- Sam

Carlos carlos:  Hmmm... Your folder structure is appearing, but you still
aren't seeing any images.  What version of windows are you running?

One thing that you could try, is creating a shortcut to ChessV.exe.  Then
edit that shortcut by right-clicking and selecting 'properties.'  Then,
in the text box labeled 'start in' make sure it has the proper path to
ChessV.exe.  Then run it with the shortcut.  The idea being that you are
trying to make sure that the current directory for the ChessV process is
the correct one...  It looks for all images (and include files, and
opening books, etc) in subdirectories relative to the current directory.

Failing that, more radical experimentation will be required...  But we'll
get it working.

I notice that your documentation accompanying the ChessV 0.9 program is a
Microsoft Word file (*.doc).

If you, as an author, prefer an Adobe Acrobat file (*.pdf) which preserves
the exact graphic representation of the document as you saw it and wrote it
(without any possible font substitutions), then I would be glad to send you
my Adobe Acrobat 4.0 (Standard) Full on 1 CD which I have recently replaced
with Adobe Acrobat 6.0 Standard Full.

Most readers (myself included) prefer *.pdf files because they open faster
and are very flexible upon display.

I think it is probably compatible with whatever version of Microsoft
Windows NT you are using.

If you issue a mailing address for you to me privately via my E-mail
address, then I can send it to you immediately USPS.  Rest assured, it is
authentic software, still in perfect condition.

Hi, Ed.

Do we know it's the ChessV program that's being implemented in these games? Couldn't that just be someone's handle? I mean, 'ChessV' might not even know about the ChessV program.

If we don't know, it could be proven one way or the other easily enough, I imagine, by going through some of the games and finding out whether the moves accord with that which the ChessV program would make, right?

I'll post some basic opening theory for Schoolbook later on this week. As a start, I like the way white's position looks after 1. f4 Nd6 2. g4

- Sam

Hi,

Can someone explain that opening book testing feature to me? It sounds
like a great idea! I want to do an opening book for another variant and
I'd love to figure out how to do this. I also don't understand why
you'd hafta restrict moves, cann someone explain this to? BTW I am most
interested in Janus Chess.

There are a few bugs in the program. Some of the 'Chess with Different
Armies' armies don't work, like the Andromidan Invaders and the Almost
Chess army, instead of them you get the standard army.

And in Chess with Augmented Knights the knights are not able to move
because they're pinned (!), and the Standard Knight doesn't have a
picture of his own.

and sorry for trouble.

Abdul-Rahman:  Thank you for the bug report.  Very good observations! 
These were minor problems that have been corrected.  I am also adding a
couple of tiny optimizations, and a new game or two, and perhaps a couple
more texture options for the squares, and then I will release 0.9.1.  You
can expect it to be released within the week.

NOTE:  The problem with the Andromedan Invaders has been resolved by
removing that army.  I created that army only for the purposes of testing
strange pieces used in other games, but they were never balanced in
strength with the FIDE army.  I might turn them into a real army and
reactivate them again someday.

Please continue to report any bugs that you discover.

Oh, i posted a few weeks ago, but it seems when all those dumb 'my chess
program is better than yours' posts were deleted, my post went too. 
Ok, so, what a brilliant program! And it's free! And best of all, for me
anyway, it plays Great Shatranj, and it plays very good with pawns too.
Hopefully, this program will just get better and better, congrats Greg!!

- Sam

It's still a work in progress, but is an excellent program.

Hi Dan,
Thanks, it would be interesting to see the game.  Let me know where you
think it went wrong.  It is quite possible that it involves the quiescent
search.

Dan played well. I personally think 5. ... Ah6 is a good try for black to both hold on to the pawn and to defend against the gambit.

As another note, if you give ChessV enough time to think about the move, it sees that white can force a mate after 15. Bf2.

- Sam

Sam and Dan,

Thank you both for the time that you have spent looking into this and
typing in your findings.  I appreciate it, and, with research, it will
lead to a stronger program.

It is true that development by itself doesn't guarantee anything. 
However, computer chess programs consider as many moves as they have time
to, and each sequence of moves leads to a positon.  The computer must then
evaluate that position (or, if pieces are still hanging, it plays out
winning captures before it evaluates,) but eventually a position must be
quantified with a number - the more positive the number, the better the
position for white, the more negative, the better for black.  Experience
can tell a human player a lot about what is good and what is bad, but
trying to program in too many specific scenarios makes a program worse,
because it takes too much CPU time to evaluate, and the more CPU time you
spend on evaluation, the less moves you can consider.

Lots of things can help ChessV.  Obviously, a good opening book would
help.  I am working on an opening book for Janus Chess, but it takes time.
 Also, evaluation of position gives pieces a bonus or penalty based on the
square it occupies (a piece-square-table.)  Such tables can be different
for each type of piece, and they can be different in the opening vs.
midgame vs. endgame.  Clearly the piece-square-tables for Janus Chess (and
all other 10x8 variants for that matter) could be improved.  I'll look
into the current tables, and, based on the game Dan has posted, I'll try
some experimentation.  Finally, I think that there is probably a bug
buried somewhere deep in the move-search functions that is proving very
difficult to isolate ...

Thanks again to you both.  I'll study what you have posted and keep you
posted!

- Sam

What I did was make the pawn worth on 333 points, the rook only worth 1666 points, the queen worth 3000 points, and so on. What this does is make factors not directly having to do with material, such as the position of the pieces, three times more valuable. Once I did this, this is how ChessV handled Dan's gambit play:

1. Ah3 e5 2. f4 exf4 3. Nd3. Stock ChessV tries too hard to hold on to the pawn here: 3. ... g5?. However, by tweaking ChessV to only be one-third as greedy, ChessV responds with the much more sensible 3. ... f5 or 3. ... Ng6, depending on how much time we give ChessV to think about the position.

My experiments show that tweaking like this, when done for the course of the entire game, will make ChessV make some unsound sacrifices in the late mid-game and end-game, resulting in the 'stock' ChessV winning the game. However, if I have the tweaked version of ChessV play white only for the first ten moves, than give the stock pieces to the normal ChessV, the result is the same as giving both sides the stock pieces: White wins the game.

For Greg's info, this testing was done at an I-depth of 7 and with pruning and razoring disabled.

If Dan is interested, I'm willing to see how well he does against the tweaked ChessV (for the first ten moves, anyway).

- Sam

What I have published of John's (with his permission, of course) is his notes on one of his 2001 Grand Chess world championship games.

- Sam

Dan, I've done some more significant tweaking today, primarily aimed at making sure it doesn't fall too far behind in development just for a pawn or two. It now makes better moves in the situations in your previous game. How much better it is overall, I cannot say, but it is almost certainly much better than Sam's modified version, as I have made a number of improvements in the last 2 weeks. If you're up for a game against the current iteration, just start a game with Game Courier, and let me know what I-Depth you would like (I have enough computing power to go up to 12 or 13, but I would recommend more like 9 or 10.) Thanks!

Zillions Save Game File Version 0.02 HH
RulesFile=C:\Zillions\3rd_party\largechess\Chess,_Large.zrf
VariantName=Janus Chess
1. Janus i1 - h3
1. Pawn e7 - e5
2. Pawn f2 - f4
2. Pawn e5 x f4
3. Knight c1 - d3
3. Pawn g7 - g5
4. Pawn e2 - e3
4. Pawn f4 x e3
5. Bishop g1 x e3
5. Pawn h7 - h6
6. Knight h1 - g3
6. Knight c8 - d6
7. Janus b1 - c3
7. Bishop g8 - h7
8. Bishop d1 - h5
8. Pawn i7 - i6
9. Janus h3 - g4
9. Queen f8 - g8
10. Queen f1 - e2
10. King e8 - f8 @ f8 0 0
11. Knight d3 - c5
11. Bishop h7 - f5
12. Knight g3 x f5
12. Pawn i6 x h5
13. Janus c3 - e5
13. Pawn h5 x g4
14. Knight c5 x d7
14. King f8 - e8 @ e8 0 0
15. Bishop e3 - f2
15. Bishop d8 - e7
16. Janus e5 x d6
16. King e8 x d7 @ d7 0 0
17. Queen e2 x e7
17. King d7 - c6 @ c6 0 0
18. Knight f5 - d4
18. King c6 - d5 @ d5 0 0
19. Queen e7 - e5

- Sam

1. Af3 Nd6 2. Ng3 f5 3. Nd3 Nhf7 4. h3 e6 5. BI3 h6 6. Ah5 Bh7 7. Ke1?

Zillions, for mysterious reasons, made a meaningless king move.

7. ... I6 8. Af3 MI7 9. Bxd8 Qxd8 10. Nc5 Ng5 11. Ae5 Nf7 12. Ad4 Ad6 13. Mj3 Qe7

ChessV now has Zillions on the run. With a better pawn structure and two more pieces developed, black has more than equalized and now controls the game.

14. Nd3

At this point, Black can force the win of a piece. The moves to do so are left as an exercise for the reader.

In the game played, White never recovered and Black (ChessV) eventually won.

Awkward play by Zillions in the opening. But Zillions can easily be made to 
make good pawn opening moves by introducing rewards for such moves. 
As soon as Zillions has moved two pawns he continues to move pawns and 
pieces in a natural way. One can also introduce a reward for castling, and 
punish early queen moves. If one makes these additions to the code then 
Zillions plays chess very humanlike and positionally interesting. The effect is 
remarkable. Zillions's style is quite humanlike because it plays such a 
varied game of chess. It also understands to attack with the pawn on the 
flanks. It is sad that Zillions programmers don't use these tricks because 
there are so many implementations where Zillions plays too much with the 
pieces in the opening, which makes the games less interesting, and the 
play much weaker. You can have a look at the code in my zrf's. In most 
cases you can simply copy it, although it can certainly be improved in many 
ways. Note that I have often also added links from the corner squares. This 
simple trick is a good idea because it discourages Zillions from wasting 
king moves to the corner squares, something which is even more important 
in the Gustavian case.

Version 0.9.1 released

new games: This version adds support for a new class of games - the diagonal games, Diagonal Chess, Diamond Chess, and Legan's Game (all from Pritchard's Encyclopedia of Chess Variants.) These games allow you to view the board normally, or rotated 45 degrees, for a more appropriate viewing. Also, support for new 10x8 games Optimized Chess by Derek Nalls and New Chancellor Chess by David Paulowich.

new features: New square textures, and a new option to customize the 10x8 Capablanca-like games. It was already possible to customize these games by making a SGF file, but now there is a user-interface to specify the rules you want, and you are given an option to save a SGF into your include directory, making the game a permanent addition to your ChessV installation. An option to replace Chancellors and Archbishops with Ministers and High-priestesses is also present to allow one to play Christine Bagly-Jones's Capablanca Shatranj variants. Just click on Capablanca Chess variants from the start screen, and check 'Customize the Selected Game'

performance: many performance enhancements speed things up 10-40 percent, depending on the game. 10x8 variants are much faster, and have much smarter evaluation of positions.

Enjoy! Download from the project's home at sourceforge.net