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This item is a game information page
It belongs to categories: Orthodox chess, 
It was last modified on: 2005-07-01
 By Greg  Strong. Angels and Devils. Chess game where white has two Angels and black has two Devils. (10x8, Cells: 80) [All Comments] [Add Comment or Rating]
Steve wrote on 2014-02-16 UTC
opposite colored bishops are only drawish in the endgame. in the middlegame they create a stronger attack. the attacker has enhanced power on squares of one color, and the defender cannot counter it.

(zzo38) A. Black wrote on 2012-11-27 UTC

If you want to make symmetric game (I prefer symmetric game generally): Each player has one angel at queenside and one devil at kingside. (Or maybe it is better other way around; I have not tried.)

(This is very simple subvariant and so I am not making its own file, unless someone requests or if there is a lot more to write about such things than the comments.)


Greg Strong wrote on 2005-07-17 UTC
Thank you all for the usful comments.  I've decided to resolve the problem
with the A-file being safe from angels (at least for now) by reversing the
pieces (both white and black) on the h- and i-files.  This does have the
effect of eliminating the distinction between the light and dark squares;
now white has a light-colored angel and a dark-colored angel, and black
has devils on both squares.  This also addresses Sam's very valid concern
that opposite colors makes the game more draw-ish.  Of course, this means
that all the computer testing that I have done to test the balance will
have to be redone.  I'm afraid that eliminating of the a-file safe-zone
will make White more powerful.  We'll see.  I'll upload a new image and
update this page shortly.  

P.S. the new ChessV version released already incorporates this change.

Sam Trenholme wrote on 2005-07-17 UTC
My main concern, just looking at this, is the color imbalance; one player
controls the white squares; the other player controls the black squares. 
It is a maxim in traditional FIDE chess that bishops of opposite colors
are draws; I am concerned that this game may be drawish.

I haven't tested it, of course.

- Sam

Jianying Ji wrote on 2005-07-04 UTC
There's two other ways to eliminate the a-file dead zone without adding a
file:

I. switching one of the angels with one of the pawns that stands on one of
the white squares. and mirror the switch on the other side. This will result in doubled
 pawn in one column, but that could lead to some interesting tactics, or you can change
 the back pawn into a man/minion that moves as a non-royal king.

-or-

II. alter the angel/devil moves by adding noncapturing forward ferz (mfF
in Betza notation) to both pieces. which adds interesting tactical color
to the game, as the players try to block the opponent's angel/devil from
changing quarters. Also the forward ferz will suggest the wings, which is
thematic.

Peter Aronson wrote on 2005-07-04 UTCGood ★★★★
For an extra piece, why not continue the theme of capturing on the opposing color? An orthogonal Withdrawer would have that characteristic, but without being colorbound, as does orthogonal custodian capture (like Ultima Pawns). <p> While it would dilute the theme, giving White on Devil and Black one Angel would mix things up a bit and help balance matters some if it turned out that the Devil and Angel had significantly different values. <p> Another game with the theme of capture on the other color is <a href='/other.dir/interweave.html'>Interweave</a>.

Greg Strong wrote on 2005-07-04 UTC
Thank you for the comment!  Yes, I found it quite useful.  I can't believe
that I didn't notice the safe-zones!!!  Actually, I'm not that concerned
about the 8th rank being safe, but the a-file being safe does bother me
quite a bit.  

Switching the Angel on the h-file with the Knight on the i-file as you
suggest would solve the problem, but then one Angel would be on dark
squares; I like the symbolism of the Angels on light squares and Devils on
dark squares.  Your suggestion of making the board cylindrical would also
solve the problem quite nicely, but I fear that most people don't like
games on cylindrical boards.  It does make things harder to visualize,
particularly the Knight-moves.  The only other idea I have is to add an
extra file.  I'm fine with this, but what should the extra piece be? 
Chancellor?  Archbishop?  Second Queen?  Something completely different? 
I dislike the idea of Archbishop, because if I used that piece, it would
need a different name.  The black army (the 'evil' army) would not have
an 'Archbishop' (and the alternate name of Cardinal isn't any better.) 
Any suggestions would be appreciated.

Jianying Ji wrote on 2005-07-02 UTCGood ★★★★
Very interesting game, and fairly modest too, which I like. I have  a few
quick observations:

I.  a-file and 8th rank is safe from the angels neither angel can jump
over them due to the edge on the left side.

II. By switching the demon and angel on the h-file with the knight on the
i-file their coverage is expanded so only the 8th rank becomes safe from
angel-fire, and the demons cover the whole board. Aethetically, you gain a
more symmetric setup. Moreover, with the white side holding the marginally
weaker angels, the first player advantage is probably canceled.

III. to make both side even more equal, you might consider making it 7 or
9 ranks (9 being my preference, a hint of dante) instead of 8, this way
there will be no safe zone from angel-fire

IV. to make a greater hommage to your inspiration you might make the game
byzantine by joining the left and right sides of the board.

hopefully you find my comment interesting and perhaps useful...

Greg Strong wrote on 2005-07-02 UTC
Ahhhh... Thanks, Derek!  I didn't realise that that's what the
'strength' slider actually did.  That's good to know.  

However, I must point out that setting Zillions to a fixed-depth still
isn't quite the same as setting ChessV to a fixed depth.  ChessV uses a
quiescent-search whereas Zillions does not, so it would still be
compairing apples to oranges.  I will now attempt to describe exactly what
a quiescent search is, but I will do so on the ChessV page.  Coming shortly
...

As for disassembling, I have no moral problems with this, but attempting
to determine Zillions' secrets from an assembly language listing without
the benefit of comments or descriptive variable names would be like trying
to drink water from a fire hose! :)  Chess programs are really tricky
things, and I have had some difficulty understanding some of the chess
programs which are open-source!  (The developers of Zillions are
professional Chess programmers... I'm just a novice doing the best I
can.)

Thanks again,
Greg

Derek Nalls wrote on 2005-07-02 UTC
'If it's a dead product, it sure would be nice if they would open-source it ...' <p>For your private purposes of furthering the development of ChessV, I see no harm in your attempting to reverse engineer the main Zillions program *.exe via a decompiler. Some may strongly disagree, however.

Derek Nalls wrote on 2005-07-02 UTC
'Problem is that while ChessV has the option to search to fixed-depth, as far as I know, Zillions does not have this option.' <p>Actually, the Zillions program will let you select a search-depth by number of plies. This capability is sure as Hell well-hidden, though. <p>Deep-linking at the Zillions web site is not supported. Just work your way to: <p>Zillions Of Games <br>Discussion Forum <br>Desired Features For Zillions Of Games <br>Time Keeping <p>Read the messages by Derek Nalls and Jeff Mallett.

Greg Strong wrote on 2005-07-02 UTC
Larry, you are absolutely right. Problem is that while ChessV has the option to search to fixed-depth, as far as I know, Zillions does not have this option. It would make me very happy if the developers of Zillions would add a couple of features, but all indications are that all development of ZoG has ended. If it's a dead product, it sure would be nice if they would open-source it ...

Larry Smith wrote on 2005-07-02 UTC
May I suggest that these two seperate Chess programs be compared based upon
search depth and not time.

Reasoning:  

One program may have an efficient depth search, allowing it to look deeper
faster.  So based upon time, it would always look further ahead in play. 
Giving it a slight strategic advantage.  

The other program with a less efficient depth search, and allowed to
obtain the same depth of the first program, may (or may not) 'discover'
alternate moves which the first program rejected for efficiency.

Now, I am not saying that Zillions will perform better than ChessV if it
was giving this consideration.  Only that it would be a fair evaluation of
the strength of these programs, rather than their speed.

Greg Strong wrote on 2005-07-02 UTC
I've played Zillions against ChessV in most, if not all games they have in
common.  In fact, that's how I test support for a new game.  If ChessV has
a bug that causes it to miss moves, than Zillions wins and I know I have
bugs that need fixing.  Otherwise Zillions never wins.  I typically give
Zillions a minute per move and give ChessV only fifteen seconds to help
level the playing field, but even at this Zillion's wins are extremely
rare.

Also, I've run some test cases with Betza's four main CWDA armies and
have found them to be very close as well, although I haven't run nearly
as many tests with that game as I would like.  What I really need is about
a half dozen really fast computers ... :)

Roberto Lavieri wrote on 2005-07-02 UTCExcellent ★★★★★
Interesting, I have to play a test game to see details.
Mike, I have tested CHESS V vs. ZILLIONS in ULTIMA. The results have shown
 notorious superiority of CHESS V:  10 to 0 !!!. Chess V plays ULTIMA quite
well, Zillions plays it relatively weak, I have not problems to beat
Zillions in every game I play against it, but I have troubles to beat
CHESS V, I can not do that very often, say, one victory in four games I
play against CHESS V, more or less. My estimated ratings in ULTIMA are:
CHESS V between 2000-2200 ULTIMA ELO rating (Using FIDE-Chess
terminology), and Zillions around 1700, perhaps less. I have not tested
the rest of the games.

Greg Strong wrote on 2005-07-02 UTC
<p>I will post a ZRF shortly, for completeness. However, a large number of tests have been run with ChessV, and show the armies to be very close. Running tests with searches to different depths or with different time limits lead to wins by different sides. Even tiny tweeks of evaluation parameters that seem like they should be unrelated can flip the victory from one side to the other. I really have no idea which side is better, although you are correct in being suspicious about unbalanced armies. I'm sure if we could perform a perfect analysis we would discover that one side is definitely better. But, it seems that they are so close that I'm pretty confident that even slight miscalculations by the players will override any inherrent unbalance.</p> <p>Also, I should point out that using Zillions of Games as a tool for computer analysis of chess variants is totally pointless. Zillions is an impressive program, and is a very good tool for prototyping games and getting a feel for how they play. Unfortunately, it is useless for analysis because it is incapable of evaluating positions correctly. Even in standard Chess it doesn't have a clue. It thinks that a Queen is worth less than Rook+Bishop, when a thousand years of careful study have shown that a Queen is worth more than the pair. And it can't even play a reasonable opening; it loves to move the Queen to the center of the board as early as possible. You can't really base anything on the results of test-cases run by a program that makes really dumb moves right from the start.</p> <p>A new version of ChessV supporting Angels and Devils will be available very soon, I hope. I'm still trying to stomp out one last annoying bug. Of course, it is worth noting that any existing bugs could skew the results of my computer analysis. Additionally, ChessV still relies on me to provide evaluation parameters, and those could be wrong too. Sadly, there is no perfect tool for testing such things. ChessV is still in its infancy, but for the time being it's the best we've got.</p>

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