FromHell: At first I thought that here on Brainking there couldn't be any atomic stalemate because of the definition of stalemate: "Stalemate is a situation in chess where the player whose turn it is to move is not in check but has no legal moves.". As the BK atomic implementation lacks checks, I thought that there can't be any stalemate (at least in legal positions). Your first example proves the contrary!

Concerning your second example I dare to contradict ;) My understanding of the rules is that a King can always move next to the other King, and as they can't capture each other it's not check! So Kb7 and Kd7 are allowed regardless of the check rule. Only for Kb8 and Kd8 the check rule would make a difference.

rabbitoid: "Don't ask me how the black bishop got to b8 :)" No, I won't do this, I just want to know how the black rook got to b7? :-D

rabbitoid: I first played at FICS more than a dozen years ago. They already had Fisher Random and several other "wild" variants, next to suicide and bughouse.

FromHell: They play other variants on fics now? it's been a while since I visited it. I think it was only bughouse and suicide, then.

I think there is stalemate, but nut sure. Similar to rabbitoids position:
White: Ka1, Na7, Nb8, pawn b6
Black: Ka8
After white's turn moving the pawn from b6 to b7. Black has no more moves, because no move is allowed which would explode the own king.
At Fics it would be 1-0, because there is check and checkmate, but I think at brainking it is 1/5-1/5, but not sure.

Other example:
Black: Kc8
White: Kc6, pawn c7
It's black's turn. At Fics it would be a draw, because of the checkrule there. At brainking is no check, so the black king can still move where he wants, except c7. ;)

lukulus: Just for the fun of it, I've built one:
black: Ka8, Rb7, Bb8, pawns a7, b6, c7.
white: pawns on a6, b5, c6, king somewhere. black to move.

Don't ask me how the black bishop got to b8 :)

Constellation36: no stalemate in AC.

Is there a stalemate in Atomic Chess? I assume there isn't but just in case.

nabla: Did you know that even two same-colored bishop were enough to win against a bare king ?
this shows hours

Constellation36: No need to message me, I still read that forum ! Questioning the promotion rule in Ambiguous Chess sounds very valid to me, since it is an important part of the game and I adopted it only after switching back and forth.

At first I didn't even think about it : I had "normal" promotions, i.e. by the piece owner. But a friend made me notice that it was not very consistent with the variant : the opponent is supposed to choose between all moves leading to the same square, the different promotions are (in my view) different moves leading to the same square, so the opponent should be able to choose the promoted piece.

That is for the logic, but then one must see how it plays in practice. That it weakens promotion combinations in the middlegame proved to be of almost no concern. Ambiguous Chess has its share of surprising combinations (especially but not only mating attacks), and frankly I don't think it needs queen promotions in order to spice the tactics.

The endgames are another story though. True enough, promotions chosen by the opponent make a material advantage a lot tougher to convert. A pawn is already more difficult than usual to lead to promotion, and then with the current rules, achieving the promotion is far from putting an end to the game.

I was afraid that it would make most endgames draws, in which case my promotion rule would be a bad one. I don't think that it is the case. Due to abandoning the stalemate rule, almost all pieces-only endgames that are wins in Standard Chess are still wins in Ambiguous. Did you know that even two same-colored bishop were enough to win against a bare king ? I think it makes the future of a material advantage look less bleak.

So unless my assessment of the endgame winnability is wrong, it comes down to a matter of taste. Should one have lengthier endgames, when the result might be the same, except a faster one, with the normal rules ? I like endgames, so I was tempted to answer yes, but I tried not to make my personal tastes account for too much in the balance. In the end, "all other things being almost equal", I just prefered to stick with the more logical and compact ruleset.

If you still can't stand the absence of queen promotions, check the two last diagrams of the following article : http://www.brainrook.com/archives/26-Just-one-more-chess-variant.html#extended

Constellation36: I've played a few more Ambiguous Chess games that you did. I'd say that promotion, or possible promotion is rare enough that this isn't much of an issue. And when promotion can happen, the promoting side usually already has a winning advantage.

I wouldn't call the game ruined because of it.

Constellation36: You should contact the creator of the game (that's nabla) with those details.

I have tried to play an Ambiguous Chess game and i can't say that i'm impressed with it. And that's because of the promotion rule. It really weakens the game the way promotions works.

Pawns are the soul of Chess and like that Pawns are the soul of Ambiguous Chess also. You can make nice sacrifices to just be able to promote. You can make spectacular moves to just give the chance to a poor Pawn to promote.
But this can't work in Ambiguous with the current promotion rules. The opponent will just choose the worst piece for you and the sacrifice would be pointless.

Countless endgames are meaningless with current promotion rules.

The rule from my perspective has to be changed such that the player and not the opponent to choose the piece in which the Pawn will be promoted.
That would create a much better game.

Just my 2c.

Perhaps i have this impression for Ambiguous Chess because of my first game. It has lasted 126 and still counting. :-) Perhaps this is a rare exception.

Lawless: Just say that if one controls no kings, that player loses.

My original idea was not good because the kings on a3 and h3 could be put in check right on the first move. This one is better: pawns on a3 and h3 and kings on a2 and h2.

But 10 x 10 sounds even better.

As to pawns promoting to kings: I proposed it simply because I saw no point forbidding it when there are several kings on the board anyway. However, if it were allowed, there would be a problem in positions where a promoting pawn can capture the opponent's last king. In that case, the player on the move would win, no matter what number he'd throw. For instance, in the position W: Ka1, Pb7; B: Ka8, Nh8, if black on the move throws a 2, it will be certain that white can capture black's king on his next move, no matter what. To give black at least some chance, as I think he should have, there should be some kind of a limiting rule, for example: the opponent's only king may not be captured by promoting a pawn to a king. In that case, the other player would still have a 1/6 chance to survive, as he has in standard Dice Chess.

Or if you think it makes things too confusing, we could keep the rule that pawns are not promoted to kings. Promotions are very rare anyway.

Lawless: I like the idea, but what about doing it on a 10x10 board - giving 10 pawns, and 3 kings in the back row (without losing any of the other normal chess pieces)?

... even though I would say keep the rules the same where a pawn can't promote to a king so there is less confusion (and easier programming of the game)

As everyone's probably realised by now, Dice Chess is quite random. It's not bad to have a game where even a very weak player has a reasonable chance of beating a very strong player. However, if you really want to find out who's better, you have to play two- or even three-win matches. So I think people might be interested in a game that would use the general idea of Dice Chess but wouldn't leave so much to chance.

There has already been proposed a variant of Dice Chess where the player on the move rolls two dice (as long as there are legal moves with at least two kinds of pieces), and gets to choose which one he wants to move with. I think that would be very interesting to play. (We could call it Two Dice Chess, unless it already has a name which I don't know.) But to me a different idea occurred just recently.

I propose a Dice Chess variant which could be called, for instance, Three Kings Dice Chess. The game is started with two extra pieces – white kings on a3 and h3, and black kings on a6 and h6. To win the game, a player has to capture all the opponent's kings. A pawn can be promoted into a king. Everything else is like in Dice Chess.

Apart from requiring at least three captures instead of just one, this variation would also have the advantage of blocking the pawns a and h in the initial position which would certainly make the opening strategy more challenging.

What do you think?

mangue: However, about repeating 3 times the same position or playing 50 moves without pawn moves, I am convinced no arbiter is allowed to interupt the game and therefore in case of a 3-times-repetition or a 50-moves-rules, there is no automatic draw...

Absolutely. I didn't speak about 3-fold or 50-move rule only about dead positions where it's an automatic draw.

Constellation36: I am not going to argue much longer about K against K end games as we mostly have the same view.

However, about repeating 3 times the same position or playing 50 moves without pawn moves, I am convinced no arbiter is allowed to interupt the game and therefore in case of a 3-times-repetition or a 50-moves-rules, there is no automatic draw...

KB versus KB is not a draw unless Bishops are of the same type(light squared or dark squared).
Moreover if bishops are of the same type and players want to continue they are not real Chess players!*** They can't force mate with any probable unskillful play and one can only lose on time or by resigning of the opponent, but even if someone does lose on time, arbiter will still declare the game as a draw as i've have repeatedly have said and do not repeat again.

If someone resigns the game he is in danger of being disqualified from the tournament or face any other penalties if he doesn't provide a sound reason for his resignation.

I'm not an arbiter and in all my career i have never seen anyone resign in a dead position but i believe his resignation will not be accepted and a dead position is an automatic draw even with resignation of one player.


***Chess is not who has the quickest hands. So to play a draw position that no one can win even with the most unskillful play and just try to out-time his opponent is ridiculous.

Constellation36: come on Constellation. Even it is clear to everyone here that King Bishop against King Bishop is a draw, no arbiter would interrupt the game if both want to continue. In case of a Blitz (5 min), an illegal game would still lose the game

coan.net: I think it didn't changed a lot .... for unexperienced players Black still has an advantage ... there is one or two tricks you have to discover to play well with White ... and this is the reason Pedro Martinez is talking about it ...

ChessVariant: Cheversi did have different rules when it first came out - and was VERY unbalanced. (leading stats to lean one way) - the rule changed happened awhile back. I'm not sure exactly how the stats are once the rules were changed.

It would be interesting to know though. Not sure if that is something Fencer can look up or not.

mangue:

Hi,

It's automatic. Most and in fact all arbiters would declare the draw, even if as i've said one player has lost on time.

Constellation36: even if a player lose on time, it is still draw
Hmm, yes that's right, there is absolutely no point in continuing a game with KB against KB... but the draw is not "automatic" afaik...well, anyone trying to win with time with just a king should look for another game, maybe Tennis?

What is the state space complexity and the game tree size for Cheversi? An approximation of course of the upper limit.

Pedro Martínez: how come statistics says something different ?

mangue: There is no automatic draw in chess, you have to claim a draw.

This is just wrong. If a position arose where no side can force a checkmate with any way, e.g because insufficient material occurred in the board, then it's an automatic draw no matter what. Even if one player loses on time it is still a draw. Such positions are called dead.

Imagine e.g a KNK position and the side with the single King to run out of time. Well it's still a draw.

there is almost no draw in dark chess, because you can never know if the 50 rules exist (how can you be sure your opponent did not move a pawn). So even after playing 500 moves, if your opponent still refuses to draw, you can do nothing.

But if you do not know if the opponent moved a pawn, you cannot claim a draw.

It is like the 3 times the same position. In dark chess, you often do not know what the opponent moved, so it is impossible to claim it.

Since in Dark Chess an arbiter is mandatory to exist to supervise the game and guarantee whether the rules are followed, it's easy to create a modification rule to the official Chess 50-move rule that could say, "If a position has arisen where no Pawn move and piece capture has taken place in the last 50 moves of both players, then game is a draw.".

No need for a player to ask about a draw.

joshi tm: I actually think it's the White who has some sort of advantage in Cheversi.

Here's a thought...

Black's advantage is great, but White has plenty of chance to win, if he plays one of his Knights last, isn't it? Black should play nezt to that Knight that cannot drain points for played rooks...

agentofchaos: Boom boom :)

wetware: I agree that Progressive 960 would be a good addition. Many variants could be played progressive - although I'd draw the line at Progressive Atomic! :-)

I'm sure I've said this here before:  I'm a huge fan of progressive chess, and have had the chance to play some of the world's best.  If we were ever to add progressive as a variant here at BK, I'd love to see a Chess960 (fisherrandom) version available--possibly in addition to a variant that begins from the standard chess starting position.  It would make it possible for more original analysis.

From the standard starting position, progressive is a great variant for people completely new to it, or to those who are learning the tactics and mating patterns of conventional chess.  But specialists in progressive variants would probably appreciate the chance to break new ground from move 1.

ChessVariant:
Hi ChessVariant, small world eh! :-)
I'm pleased to see there's some support for progressive.
Cheers

agentofchaos: Yeah, Im a big fan of it. It's quick and easy. Was playing it with a friend of mine a couple weeks ago. It can produce some funny and interesting mating combonations.

agentofchaos: I agree, it would be a nice addition ...
agent, you are my opponent at Schemingmind playing Atomic960 tournament ...
Cheers.

Progressive chess is a highly popular variant in OTB play but few game sites seem to offer it. The basic idea is that the number of moves a player can make each turn increases by one each turn, i.e. white initially has 1 move, black has 2, then white has 3 etc. Putting the opponent in check immediately ends one's turn, even if you have further moves left. (There is a variant in which one can only give check on the last move of one's turn.) A player in check must relieve check on the first move of their turn or they are checkmated. I think this would be a great addition to the site.

Hi. I have a tournamet Chess - Elimination in All Variations II and in two days will be deleted. There is just couple games left but in some of them i need just one-two players so I would like to ask you to fill it up please. Thank you

Key McKinnis: Because the inventor thought it would be better this way, but he changed his mind since. I asked Fencer if he could restore the promotion, but he wasn't convinced (and he doesn't like rule changes). I have played Recycle Chess with promotions and I liked it much better that way.

Why can't pawns promote in Recycle Chess?

ughaibu: Probably it is thought that because otherwise one of the knights would often be dedicated to the defensive task of enhancing the movement of its king, making the play less dynamic. But I didn't try it that way.

By the way, without the restriction about knights it might be unclear whether a knight connected with its colleague could capture a piece.

No idea there. As I see it, it would work just as well without an exception for kings. So kings could, for example give check - as long, of course, as the other king isn't protected by a knight. But since it's a rule change, it would be a separate variant.

Good point about the knights, but why the exception for kings?

ughaibu: it's explicit in the rules: "Any piece (except a king or a knight) which is guarded by a knight of the same colour..."

And by the way, the exception for the knight seems silly.

Okay, I see the kings aren't effected at all by knights. Why not??

In knight relay chess can a king give check? If not, why not?

nabla:
1. Triple check is possible. Yet very rare in practice.

2. The rule gets very interesting in combination with rule 1. If you can only put your piece in play with a normal check, the opponent can take it off the board by promoting a pawn! :D
In my region bugchess is nearly always played with the combination of these two rulez!

rabbitoid:
If the opponent has only a king and pawns left, a promoted pawn is simply removed from the board!

Rule (2) comes often into play. Early checkmates with dropped pawns/bishops on f2/f7 can be prevented by blocking the own king. This is no beginners rule but quite an interesting defense possibility. Besides checkmating is often too easy by dropping a queen.

Karthum: 1 is interesting. I suppose that it would be allowed to pick a pinned piece (which makes a triple check possible).

2 is sometimes played but is widely disapproved by the community of Bughouse (= 4-players) and Crazyhouse (=Loop Chess) players as a beginner's rule. It does not enhance the tactics, just makes them more artificial - like instead of mating by dropping a line piece 1 away from the king, dropping a line piece 2 away from the king, the opp blocks, take the blocking piece with mate.

Karthum:
1 is possible, but would make a new variant. What happens if the opponent has only a king left?

I doubt the utility of (2), the situation should arrive only very rarely. I don't think I've ever had the situation.

Two ideas for Loop-chess variation:

1. A wonderful idea would be to prevent pawns in Loop-chess from promoting normally. Instead you can pick an opponents piece on the board. The picked piece, e. g. a rook, is removed and the pawn is promoted to a rook. The opponent gets a pawn in the hand.
This brings the tactical idea of removing opposing pieces by promotion, yet carries the disadvantage of not being able to choose pieces for promotion the opponent doesn't control on the board.

2. The second idea is to prevent checkmate by Drop!
That makes good tactics more essential for attacking.

Have fun discussing this or not!