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Ovyron wrote: ↑Sun Jul 28, 2019 12:07 pm

carldaman wrote: ↑Sun Jul 28, 2019 2:52 am rather significant/radical rule changes, imo.

This is just smart draw odds.

I like it, I have been seeking for an answer to incoming chess draw death, and this could be a chess variant more fun than chess.

I wonder if RSIF is optimal, though, what about these?

RISF

White Wins = Repetition / Insufficient
Black Wins = Stalemate / Fifty Moves

RFSI

White Wins = Repetition / Fifty Moves
Black Wins = Stalemate / Insufficient

And the ones with white and black's winning conditions reversed? (IFRS, SFRI and SIRF) is there a way to test what is the best?

My support would to to FRIS (Fifty moves / Repetition = White wins, Insufficient / Stalemate = Black wins), because it's the easiest one to pronounce (though, that's arbitrary.)

Tried some of those combinations with current implementation (mostly search modification, not touching the evaluation), RSIF is close so far. But I like the idea of reversing RSIF to IFRS as you mentioned. See my other post, repetition is dangerous well perhaps for engines where it can track transpositions more accurately than humans.

I will try next the reverse of RSIF.

I see from the game you posted how the repetition rule has huge effects thruout the endgame. So here is a simple alternative:
1. Three time repetition is illegal.
2. Stalemate is a loss for the stalemated side. (old rule)
3. Bare King loses. (old rule)
4. Fifty move rule is a win for Black.

I had always assumed that this would still favor Black greatly, but in view of the importance of repetition now I'm not so sure. If it favors Black just slightly it would be okay. If it still favors Black too much some modification might make it fair.

Neat idea - I'll try to play a few games with friends who like variants.

What happens if two conflicting conditions occur on the same move?

For example, here, after black plays 1... Rc6, white plays 2. Nxc6, resulting in both stalemate and insufficient material.

[d]k1r5/8/1K6/4N3/8/8/8/8 b - - 0 1


Repetition and 50 move rule could also be triggered at the same time, as can stalemate and the 50 move rule.

I suppose it's not possible to trigger repetition and insufficient material at the same time, though, as reducing to insufficient material implies a capture, which cannot be repeated.

lkaufman wrote: ↑Sun Jul 28, 2019 5:07 pm If it still favors Black too much some modification might make it fair.

If it favors Black too much perhaps this is another idea that can be used in a human vs computer handicap match?

lkaufman wrote: ↑Sun Jul 28, 2019 5:07 pm I see from the game you posted how the repetition rule has huge effects thruout the endgame. So here is a simple alternative:
1. Three time repetition is illegal.
2. Stalemate is a loss for the stalemated side. (old rule)
3. Bare King loses. (old rule)
4. Fifty move rule is a win for Black.

I had always assumed that this would still favor Black greatly, but in view of the importance of repetition now I'm not so sure. If it favors Black just slightly it would be okay. If it still favors Black too much some modification might make it fair.

For 1
What do you do if the only legal move force three time repetition?

Is it a loss for the side that has to make the repetition move?

todd wrote: ↑Sun Jul 28, 2019 6:09 pm Neat idea - I'll try to play a few games with friends who like variants.

What happens if two conflicting conditions occur on the same move?

For example, here, after black plays 1... Rc6, white plays 2. Nxc6, resulting in both stalemate and insufficient material.

[d]k1r5/8/1K6/4N3/8/8/8/8 b - - 0 1


Repetition and 50 move rule could also be triggered at the same time, as can stalemate and the 50 move rule.

I suppose it's not possible to trigger repetition and insufficient material at the same time, though, as reducing to insufficient material implies a capture, which cannot be repeated.

In your example, White wins by both rules, it doesn't matter. If you have a bare king, the other side cannot be stalemated, so there is no conflict in this case. The repetition rule says the move that repeats is illegal, so it cannot trigger the 50 move rule. Stalemate, like checkmate, ends the game so no 50 move rule claim can be made. So I don't think there are any ambiguous situations, except perhaps K and bishop each of same color, which is insufficient material but not bare king. I would put that in the 50 move rule category, as that is what would happen if you continue playing, assuming no blunder of a bishop.

Uri Blass wrote: ↑Sun Jul 28, 2019 6:59 pmFor 1
What do you do if the only legal move force three time repetition?

Is it a loss for the side that has to make the repetition move?

Stalemate means no legal move available, a move leading to three time repetition is as illegal as moving a pawn backwards, so yes.

lkaufman wrote: ↑Sun Jul 28, 2019 7:04 pm

todd wrote: ↑Sun Jul 28, 2019 6:09 pm Neat idea - I'll try to play a few games with friends who like variants.

What happens if two conflicting conditions occur on the same move?

For example, here, after black plays 1... Rc6, white plays 2. Nxc6, resulting in both stalemate and insufficient material.

[d]k1r5/8/1K6/4N3/8/8/8/8 b - - 0 1


Repetition and 50 move rule could also be triggered at the same time, as can stalemate and the 50 move rule.

I suppose it's not possible to trigger repetition and insufficient material at the same time, though, as reducing to insufficient material implies a capture, which cannot be repeated.

In your example, White wins by both rules, it doesn't matter. If you have a bare king, the other side cannot be stalemated, so there is no conflict in this case. The repetition rule says the move that repeats is illegal, so it cannot trigger the 50 move rule. Stalemate, like checkmate, ends the game so no 50 move rule claim can be made. So I don't think there are any ambiguous situations, except perhaps K and bishop each of same color, which is insufficient material but not bare king. I would put that in the 50 move rule category, as that is what would happen if you continue playing, assuming no blunder of a bishop.

Ah, I forgot that you also proposed rules. I meant to reply to the OP, whose rule is that stalemate wins for white and insufficient material wins for black, so my position would create a conflict according to Ferdy's rules.

As it turns out, I've already tried your version of this variant (except for the "50 move rule = black wins" part - we didn't address the 50-move rule) years ago. I think I was inspired by a discussion in TCEC chat where people were trying to come up with drawless chess variants. We played a bit more materialistically than usual and were a bit wary of playing white in sharp openings that tend to have a lot of attacks that end in perpetuals. But we didn't give more than a few minutes thought to the strategy.

Another way, in the old days when hardware was limited (few hundred games) and depths were low I maintained a statistic that counted games that ended in a draw while during the game one side had a winning score (say 2.50).

I've just realized that I don't like the 50 move rule used for this. It just means that one side wins if for 50 moves there's no capture or pawn move. But the whole point of it is that there's a side that can't make progress towards a win.

Since win will happen, a side is making progress towards a win no matter what, so why 50 moves? If a side wins after some period without pawn moves or captures, maybe it should be tested what number to use for this is optimal (it's unlikely it's 50.)

Also, we can start splitting hairs and do this:

No capture of pieces after x moves: White wins
No pawn moved after y moves: Black wins