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Computer resistant chess variants[Subject Thread] [Add Response]
John Whelan wrote on Wed, Dec 9, 2015 07:32 PM UTC:
I'm no expert on this.  My understanding is that what one should look for
are a huge variety of possible legal moves per turn, and natural and easily
visualized strategies, gradually developed over multiple turns.  It might
help to have a large board, many pieces with geographically localized
powers (that cannot cross the board in a single swoop), and multiple moves per turn with separate pieces.

John Whelan wrote on Sun, Dec 13, 2015 12:27 AM UTC:
Looking at Sac Chess, I'm not sure it's ideal. There are alot of different pieces, maybe too many. A computer would have no trouble keeping track of all the move options, but a human might. And the board is so crowded that it might actually limit move options. <P> I agree that a big board and more pieces might help some; but it might be better if more of pieces were more modest in their power levels, and if there were not so many capable of sweeping clean across the board for a surprise mate. <P> Agree with your idea that Shogi-like drops might help. I also like your idea of limiting the Shogi-like drops to the near board, so that such drops are more strategic and less tactical. <P> Another idea might be that if the power of a piece depends not only on its position, but on its orientation (i.e., which direction the piece faces), like the Rotating Spearman in <a href="../large.dir/contest/cenchess.html">Centennial Chess</a>, then this likewise increases move options and board complexity. <P> I once had the idea that a system that allowed each player to make 2 moves per turn, with separate pieces, might (with appropriate limitations on the double-move to prevent rapid shifts in the state of the board) increase the difficulty level for computers. In FIDE Chess there are roughly 30+ legal moves per level in mid-game, but if each player is allowed to pick a combination of 2 such moves, then the number of legal options per turn increases into the high hundreds. This, however, is just an idea. I don't know if it would actually work this way. <P> I did however construct a 2-move variant, partly with this idea in mind, which I call <a href="http://www.chessvariants.com/index/msdisplay.php?itemid=MS2prongedchess">Two-Prong Chess</a> . It should work with most chess variants, and I find it enhances large-chess variants by making them more dynamic. My subjective experience trying it, is that it feels much like regular chess, and probably does not interfere overmuch with the strategic powers of a human player.

John Whelan wrote on Sun, Dec 13, 2015 03:26 AM UTC:
The link I provided for Two Prong Chess does not work for me. Here's me trying again: Two-Prong Chess It's really not like Progressive Chess at all; and would work fine with your Sac Chess.

John Whelan wrote on Mon, Dec 14, 2015 08:57 PM UTC:
My own limited understanding might be by way of the following illustration.
 Let's say (only by way of illustration) that a game offers 10 reasonable
move options per turn, and that a computer calculating likely futures has a
calculation limit of 10 billion.  It will reach this limit after 10 moves. 
But if there are 20 reasonable move options per turn, it will reach this
limit before 8 moves; if 40 options, then before 7; if 80, then before 6
moves; if 160 then before 5 moves; if 320, then before 4 moves.

None of this helps the human player unless the human can, in some
significant respects, think ahead and see strategic options, using his
natural or intuitive strategic powers, at a number of moves ahead beyond
which the computer can calculate.

That's what I'm not seeing from your "Sac Chess".  It might be huge fun and
result in beautiful unpredictable chaos; but that's mainly from a human
perspective.  If it offers a human a better chance to see several moves
ahead then a computer, then I am not seeing or understanding the strategy
by which the human could achieve this.  

Which brings me to a suspicion and worry that I cannot fully shake off -
that a computer-resistant chess might also be a boring chess variant.

John Whelan wrote on Mon, Dec 14, 2015 10:49 PM UTC:
Muller, it's not quite that simple.  Human brains can still do things that
computers cannot.  That's why humans continued to be able to beat chess
programs for many many many years after the raw speed and calculating power
of the computer vastly exceeded that of the human brain.  Those days have
passed, but the computer still depends for its success on that (now
increased) raw calculating power, and it might still in theory be possible
to construct a game that more significantly rewards natural human strategic
thinking, while granting a much lesser benefit to the raw calculating power
of the computer.  Human skill, unlike that of the computer, has never depended on the ability to precisely anticipate millions and billions of positions.

John Whelan wrote on Mon, Dec 14, 2015 11:40 PM UTC:
Muller, It is already true that some games are more computer resistant than
others.  Checkers (beaten in 1994) is less computer resistant than Chess
(beaten in 1996), which is less computer resistant than Arimaa (beaten
recently, but still, probably more computer-resistant than standard chess
in relative terms), which is less computer resistant than Go (where humans
still reign supreme).

Also, Computer resistance is a relative quality.  If the top computer can
beat the top human, a game might still be somewhat "computer resistant" if
a top human can still give an affordable computer a run for its money.  If
I play online against someone, chances are he's not getting help from the
top computer in the world.

Humans still have their strengths, and a game can cater to them.  I just worry that it might be a boring game.  I've never been fascinated by Go, for instance.

Of course, if you're just postulating the continued advance of computers until they can do ANYTHING as well as humans can or better ... then I don't necessarily deny it.

John Whelan wrote on Tue, Dec 15, 2015 01:25 AM UTC:
There's an interesting article by Fritz Juhnke online about creating
computer resistant variants.

Per the article, the inventor of Arimaa at first considered multi-move
chess, but decided it would end up giving computers an advantage.  That, if
correct, shoots down my idea.

But per the suggestions he gives, I think he'd also frown on any suggestion
that Sac Chess would be computer resistant.

John Whelan wrote on Tue, Dec 15, 2015 04:28 PM UTC:
Muller, your use of the phrase "proper evaluation criteria" seems
arbitrary.  Obviously, evaluation criteria exist, or some Go players would
not be better than others.  To label such criteria improper, merely because
humans can assess them better, would sound like computer sour grapes, if
not for my conviction (inspired by my reluctance to accept that computers
can already do anything humans can) that you are probably human.

Go also has short-term goals and short-term captures.  But computers
cannot foresee long term, and even the relative short-term might not be short enough.  The branching factor, as
well as the number of moves involved in even relatively short-term victories, is a part of this.

In Chess, gaining material is indeed "a way to go" as an interim goal for those (human or computer) who cannot foresee the final checkmate.  But it can be a trap,
leading in the longer run to checkmate or loss of even more material.  The
problem, in Chess, is that the computer can see far enough ahead to know
the difference.  Again, the branching factor, and the number of moves
involved, is a factor.

Still, your point about material is well taken.  In Chess, material gains
are almost always good, and if there is a trap, it is generally sprung
quickly or not at all.  When it is sprung quickly, a computer can foresee it.  But consider that this need not be equally true in
all types of Chess.  For example if you play on a larger board, with more
geographically localized pieces, then a trap might take longer to spring,
and the warning that how much material you have might be less important than where your
pieces are on the board, is something that might remain true for a longer period.

John Whelan wrote on Tue, Dec 15, 2015 06:36 PM UTC:
Sorry, I still don't know what you mean.  The rules of Chess and Go, and
the criteria for victory, are equally unambiguous.  Computers use similar
methods to analyze both.  It's just that with Go, the computer runs out of
steam sooner, because of the large branching factor and the higher number
of moves.  Of course, it is also important that these factors do not
prevent human skill from operating in ways that computers cannot yet
replicate.

But no, I am not denying that there may be ways to fine tune a computer program to more closely approximate human skill.

Sac Chess. Game with 60 pieces. (10x10, Cells: 100) [All Comments] [Add Comment or Rating]
John Whelan wrote on Wed, Dec 16, 2015 11:22 PM UTC:
I don't think one can be too dogmatic about the relative value of pieces across all contexts.

It is very useful in Chess to throw lesser pieces onto the front lines for profitable exchanges, while using the Big Guns for backup.  Whether a Big Gun is worth more to you than 2 lesser value pieces will probably depend on the balance between Big Guns and lesser pieces that you already have.

But I think that generally, a singe piece that combines the powers of two lesser pieces would be worth less than those two pieces.  As evidence of this, I offer the fact that a Queen controls twice as many squares as a Rook (and as many squares as 2 Rooks), but is worth less than two Rooks.

A Bishop has the same firepower as a Rook, in terms of the number of squares it controls.  The reason a Bishop is worth less than a Rook is that a Bishop is confined to half the board, and the Rook is not.  A Queen gains the Bishop's extra firepower without suffering from its limitations.  This is the reason why a Queen is generally worth more than a Rook and Bishop combined.

This logic does not apply to the Amazon.  Neither the Knight nor the Queen is limited in the way the Bishop is; so a piece that combines their powers should be worth less than the value of Knight+Queen, not more.

I agree that 10x10 board size will tend to increase the value of unlimited range pieces.  On the other hand, the SAC chess board is rather crowded, and this may tend to decrease the value of ranged pieces (while increasing the relative value of the knight's unblockable movement). SAC chess starts with 60% of the board occupied, as opposed to 50% for FIDE chess.

John Whelan wrote on Wed, Dec 16, 2015 11:39 PM UTC:
>  You're doing your math wrong. A Queen at 9 points is worth more than 
>  a Rook (5 points) + a Bishop (3.25 points).

There's nothing wrong with my math.  If firepower were the only issue, Rooks and Bishops would be worth the same (5).  A Bishop is worth less because of its limitations.  A Queen is worth more than Rook and Bishop because it gains the Bishop's firepower without suffering from its limitations.

Imagine a piece that had the power to move like a Rook and, in addition, the power to move diagonally but ONLY along black diagonals.  This piece would come closer to combining the powers of a Rook and (black-square) Bishop.  And its value would be less than the combined value of those two pieces. 

A Queen does not really combine the power of one Rook and one Bishop.  It might be closer to the truth to say it combines the powers of a Rook and both Bishops.

John Whelan wrote on Thu, Dec 17, 2015 12:22 AM UTC:
>  If the Queen is your example, you must compare the Queen to the value of a Rook plus a Bishop, not to the value of two Rooks.

Okay.  But haven't I already done that?

A Queen does not really have just the power of a Rook and Bishop.  It has the power of a Rook and both Bishops.  It can move like a Rook, and in addition, can move diagonally on black diagonals, and diagonally on white diagonals.  

As to "firepower" (the number of squares it controls at one time), the firepower of the Queen is nearly equal to that of two Rooks.  Or to put it another way, it has the firepower of a Rook and a Bishop (both of which can control an almost equal number of squares), but does not suffer those limitations that restrict the Bishop to one half of the board (which limitation reduces the Bishop's value compared to the Rook, despite it's almost-equal "firepower").

John Whelan wrote on Thu, Dec 17, 2015 01:14 AM UTC:
On consideration, it seems I must revise my position that the one-color only limitations of the Bishop seriously affect its value.

The Rook controls 14 squares on an empty 8x8 board.  The Bishop controls 13 at most (when in the center of the board) but more often only 7 (when at the sides).  The average for the whole board seems to be control of 8.75 squares, though in practice that number will be higher as players will tend to position their bishops to best advantage (i.e., they will tend to avoid sides and corners).

Divide both by a similar factor (2.8) and you get 5 for a Rook, and 3.125 for a Bishop (or perhaps higher in practice for the reasons stated), which is not too different from their relative values as found in practice.

John Whelan wrote on Thu, Dec 17, 2015 10:21 PM UTC:
Muller, thank you for your analysis.  You gave me some things to think about.  However, I'm still not sure we're entirely on the same page.

You mention the Wazir, and how it's barely worth more than a pawn.  So I asked myself, why would that be?  I now hear that the analogous-but-diagonal Ferz is considered more valuable, despite being colorbound.  Why would that be?  They have equal "firepower".  A little thought produces the answer.  The Wazir is devalued by its lack of mobility, especially on a board crowded with pawns (and others).   A Ferz can easily slip through pawn formations (which depend on diagonals), but a Wazir cannot.

These same considerations will impact a Rook when compared to a Bishop.  With that in mind, it seems likely that the colorbound nature of the Bishop does affect its value, but this probably does little more than balance the pawn-bound limitations of the Rook.

This also explains the phenomena you discuss.  A rook/knight combo breaks the rook's pawn-bound status, and is probably more valuable than a knight+rook as separate pieces.  A bishop/knight combo breaks the bishops color-bound status, and is probably more valuable than a knight+bishop as separate pieces.

But a queen already breaks both these limitations, and a Knight's powers probably don't break them much further than they are already broken.  I therefore still doubt very much that an Amazon is worth more than the combined value of Queen + Knight.  

The pawn-synergy factor brings me back to my original point.  The value of a piece will depend on what else is on the board and the synergy or lack thereof between them.  "Sac Chess" throws us all for a loop by radically altering the other pieces on the board.  It's guesswork, and the value of a piece as measured in one context (such as a close approximation of FIDE Chess), will not necessarily apply here.

Dragonchess. A three-dimensional fantasy variant. (3x(12x8), Cells: 288) (Recognized!)[All Comments] [Add Comment or Rating]
John Whelan wrote on Sat, Dec 19, 2015 09:54 AM UTC:
The text here correctly says that the Dragon cannot move and use his "capture from afar" ability in the same turn. However, it would be clearer if it specified that the "capture from afar" ability counts as a move. Hence, not only can the dragon not move that turn, but none of your other pieces may move either. The capture is your move.

Sac Chess. Game with 60 pieces. (10x10, Cells: 100) [All Comments] [Add Comment or Rating]
John Whelan wrote on Sat, Jan 23, 2016 02:28 AM UTC:
I am interested this variant because I am fascinated by large chess variants, and this variant is LARGE (Dragonchess beats it though).   One thing bothers me, though.  The Queen.  She retains her status as the only unique piece other than the King.  She retains her place of honor by the King's side.  But there is nothing special about her in this version.  She is trumped to two Amazons, and a number of other pieces come close to her in value.

John Whelan wrote on Tue, Jan 26, 2016 12:17 AM UTC:
One solution would be to have two Queens, and to put the Amazon in the place of honor next to the King (and perhaps change their names).  The only thing stopping this would be a desire to keep both the traditional names, and their traditional significance.

Another solution might be to give the King some kind of enhanced movement power while the Queen is in play, such as an ability to switch places with the Queen, or an ability to jump over a Queen.

Another solution might be to give all the knight-combo pieces, including the Amazon, limited range:   2 or 3 squares (distinguishing them from the King-combo pieces). This would leaving the Queen, Bishop and Rook as the only full-range pieces.  This would leave most of the pieces geographically localized, which fits the advice of some who have discussed computer resistant variants.

There are any number of possible solutions.

John Whelan wrote on Tue, Jan 26, 2016 01:53 AM UTC:
Re:  "you can't please everyone" - No, but it is not as though I ever demanded you do 1 Amazon & 2 queens.  It was 1 of several alternative suggestions.  And these were merely examples to suggest that the issue is not insoluble.

Re: "close to standard chess in spirit".  Seems to me the pieces of FIDE chess have a high degree of ability to threaten each other without being threatened back.  Even the Queen, the most powerful piece on the board, can be threatened by the 2 knights.  Seems to me a lot of that is lacking here, for all the variety of pieces.  If an opposing piece cannot threaten you back, it is probably less powerful.

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