The Peace-Chess Challenge

[kbhearn]

Regarding an evaluation - certain pairs of unions are probably advantageous to one side vs another - i.e. having your queen unioned to a lesser piece or pawn is a penalty as it greatly detracts your ability to set off a winning capture chain that you don't have sole control of your most powerful piece. Whether it'd be better for the side hugging your queen to be using a pawn to do so (might not be able to move the queen away enough) or a better piece is an interesting question. I think ideally you'd have a material table that individually evaluates each hugging pair and non-hugging piece and just tune that.

It's conceptually an interesting game - when you have a way for it to be played online or vs an early concept engine i'll take another look :)

[kbhearn]

Regarding repetition though, i don't know that 3-fold repetition is draw is going to work out ok. i.e. imagine the situation where side A threatens to win by moving queen-hugging-bishop into position where it can be chained in for a win. and side B of course moves it away. Obviously if A's position is truly just better they then might make another move to avoid the repetition - but if B's threat in moving away is enough, repetition might be all there is to be had.

It might be better to have 'repetition is illegal' instead for the game to be decisive enough often enough but it's hard to say without actually playing games first.

[AlvaroBegue]

Total number of unions increases could be 'progress' - a piece can only be released from a union if another piece enters a union, so number of unions cannot go down. in the case that all non-kings are in union, the game must be drawn.

I don't understand that last part. Why would it be a draw? Is that a rule you are proposing?

[kbhearn]

Since the kings can't initiate a union, and the only way pieces can leave a union is by another piece initiating a union, only kings in non-union has to be a draw - there's just no way to hug a king anymore.

[AlvaroBegue]

Since the kings can't initiate a union, and the only way pieces can leave a union is by another piece initiating a union, only kings in non-union has to be a draw - there's just no way to hug a king anymore.

Oh, that makes sense. So unions create weird movement opportunities for free pieces, but you need a free piece to initiate the attack.

What a strange game.

[hgm]

Total number of unions increases could be 'progress' - a piece can only be released from a union if another piece enters a union, so number of unions cannot go down. in the case that all non-kings are in union, the game must be drawn.

'Progress' is what brings you closer to a win. If you get closer to a draw, declaring the draw earlier through the 50 move rule just saves time. The only reason to be reluctat in declaring draws is that you would rob someone who can force a win, but only a lengthy one, of a full point. This is why you reset the counter on indications that a player might be on his way towards forcing a win.

Having a Queen being hugging a Pawn does seem a disadvantage for the Queen side. But it is only a temporary one, as you can move another piece in the union to release the Queen. This is easy to achieve, because the Pawn cannot easily run away, and with your Queen move you can easily bring it to a location where the Pawn doesn't have any moves at all. So it is comparable to having the Queen on a low-mobility square in Chess, not like being a Queen behind. You might be off worse when the Queen is coupled to a more mobile piece, such as a Bishop. But that of course also impairs the Bishop.

As to the repetition example: I think this just shows that a Bishop hugging a Queen is pretty weak, not useful for attack. Its task is to subvert the usefulness of the Queen it is hugging, and if it could do that for 100% it would already be a great success. There is really no need to do anything offensive with it in addition. More likely the powerful Queen makes the Bishop 100% useless, while The Bishop can be happy to make the Queen 50% useless. That would still be a good deal, for the Bishop.

And indeed, it is a strange game, quite different from normal Chess. Some of the demo games I saw have the Queen 'capture' into the Pawn shield of a castled King, waiting to be activated. Carrying it away with the Pawn is not very effective if the Q-P union was right in front of the King, as it would keep the King in the line of fire of the Queen.

For a video of some demo games, see here ("gameplay examples", about halfway the page). Beware that even my untrained I can see that the player on the left is totally naive, and doesn't see any threat coming.

[Dirt]

in the case that all non-kings are in union, the game must be drawn.

I would think so too, but it's strange that it's not mentioned in the rules.

[kbhearn]

Total number of unions increases could be 'progress' - a piece can only be released from a union if another piece enters a union, so number of unions cannot go down. in the case that all non-kings are in union, the game must be drawn.

'Progress' is what brings you closer to a win. If you get closer to a draw, declaring the draw earlier through the 50 move rule just saves time. The only reason to be reluctat in declaring draws is that you would rob someone who can force a win, but only a lengthy one, of a full point. This is why you reset the counter on indications that a player might be on his way towards forcing a win.

I more view progress as 'this game must have an end and we're getting closer to it whatever that end is' - that said i doubt any type of 50 move rule will be much of a hindrance to 'real wins'. I don't think distance-to-promotion is a very good qualifier for a game where pieces are being carried away frequently, but how often it'll matter i don't know. Mostly i suspect the 50 move rule will be important for computers that have unlimited patience and would happily play 10000 moves without accomplishing anything.

Having a Queen being hugging a Pawn does seem a disadvantage for the Queen side. But it is only a temporary one, as you can move another piece in the union to release the Queen. This is easy to achieve, because the Pawn cannot easily run away, and with your Queen move you can easily bring it to a location where the Pawn doesn't have any moves at all. So it is comparable to having the Queen on a low-mobility square in Chess, not like being a Queen behind. You might be off worse when the Queen is coupled to a more mobile piece, such as a Bishop. But that of course also impairs the Bishop.

Indeed - hence the need to tune every pairing individually to see how much each type is how much of a penalty and for which side. It does seem though that for instance typical f7/h7 attacks on the castled king might be more fierce than ever with free pieces. And these tactics should probably rule the middlegame - endgames with most pieces in union are what evaluation would need to be superprecise about.

As to the repetition example: I think this just shows that a Bishop hugging a Queen is pretty weak, not useful for attack. Its task is to subvert the usefulness of the Queen it is hugging, and if it could do that for 100% it would already be a great success. There is really no need to do anything offensive with it in addition. More likely the powerful Queen makes the Bishop 100% useless, while The Bishop can be happy to make the Queen 50% useless. That would still be a good deal, for the Bishop.

I still would worry that without either repetition-illegal or 'no moving the piece your opponent last moved' that optimal play might fall into the 'i do this, no you don't, yes i do' repetitions - especially with queen-hugging-queen where every move IS undoable :p

And indeed, it is a strange game, quite different from normal Chess. Some of the demo games I saw have the Queen 'capture' into the Pawn shield of a castled King, waiting to be activated. Carrying it away with the Pawn is not very effective if the Q-P union was right in front of the King, as it would keep the King in the line of fire of the Queen.

This could wind up akin to a coffeehouse sacrifice - Very good in practice against fallible opponents, occasionally even correct, but potentially theoretically losing in most situations - i.e. if the retreat of the queen can be blocked at the same time as the way to chain into it you could just be 'down a queen'.

[hgm]

I still would worry that without either repetition-illegal or 'no moving the piece your opponent last moved' that optimal play might fall into the 'i do this, no you don't, yes i do' repetitions - especially with queen-hugging-queen where every move IS undoable :p

Indeed, a Q-Q hug could be problematic. At first glance it would be a neutral coupling, making the Queens equally useless for both players. As you say, it is easily seen it is totally useless for a side that wants to win, as any move he does with it would immediately undone by the opponent. But for the player that is behind it then is a useful asset, because effectively he has the exclusive use of it. So it is a concern whether this can be a sufficiently large stabilizing factor to make the game very drawish after a Q-Q hug.

Perhaps undoing the previous move should be forbidden,

This could wind up akin to a coffeehouse sacrifice - Very good in practice against fallible opponents, occasionally even correct, but potentially theoretically losing in most situations - i.e. if the retreat of the queen can be blocked at the same time as the way to chain into it you could just be 'down a queen'.

Indeed, this is quite possible. I do't think the quality of play I have seen in any of the demo games was above that level. This is why I would like to have an engie to play it, so that the rules can be evaluated more objectively, and perhaps adjusted to give a better game.

[Arpad Rusz]

I like this game but I would prefer that the kings could capture. Otherwise positions with less than 32 man are illegal which is bad for composing problems or studies. Also the checkmate positions would be more natural if the king could take an undefended attacker.