Draw by 3 fold repetition...

[Pi4Chess]

Thanks for all your participations in this topic. You have helped me express what i was thinking about this 3 king's check repetition draws happening and my wondering about the adressing of this.

[Ras]

@ras : when you Say a draw is a draw, are you saying that when SF evaluates a position as a draw he is always right ?

The problem isn't the draw. It's that the alternatives Stockfish can see would be worse, and not just by a tiny little bit. That's what the contempt is for, to prevent the engine heading for a draw just because of minor eval noise.

As for why a draw is a draw: because draw through repetition earns you half a point, just as draw through insufficient material or stalemate.

[Pi4Chess]

@ras : when you Say a draw is a draw, are you saying that when SF evaluates a position as a draw he is always right ?

The problem isn't the draw. It's that the alternatives Stockfish can see would be worse, and not just by a tiny little bit. That's what the contempt is for, to prevent the engine heading for a draw just because of minor eval noise.

As for why a draw is a draw: because draw through repetition earns you half a point, just as draw through insufficient material or stalemate.

Ok so conptempt is already adressing this with I assume testing has lead to 24 contempt to be the number with better results.

If SF always search for opponent's possible checks to its king's in say next n moves we can then assume that when a 3 repetition by forced checks occurs SF is never taken by surprise then ?

[Ras]

If SF always search for opponent's possible checks to its king's in say next n moves we can then assume that when a 3 repetition by forced checks occurs SF is never taken by surprise then ?

Yes. Stockfish knows that this will be draw through repetition. In particular, checks are extended in search so that Stockfish should see such lines already at relatively low search depths.

[Pi4Chess]

If SF always search for opponent's possible checks to its king's in say next n moves we can then assume that when a 3 repetition by forced checks occurs SF is never taken by surprise then ?

Yes. Stockfish knows that this will be draw through repetition. In particular, checks are extended in search so that Stockfish should see such lines already at relatively low search depths.

Ok. may be as i said telling SF the "difference" between a SURE draw by rule of repetition and an evaluated draw (other than egtb) could open a very tiny window of improvment even if i don't know how.

[Ras]

Ok. may be as i said telling SF the "difference" between a SURE draw by rule of repetition and an evaluated draw (other than egtb) could open a very tiny window of improvment

The alternative to allowing repetition in the example positions wasn't an endgame draw. It would have been a clearly worse-than-draw continuation. Just use Stockfish in multi-PV mode and see how the best non-drawing move would fare.

[syzygy]

If you think that some move should be different then you should give a position and say what move stockfish played and what it should play based on your opinion.

I am just asking those who know how engines are coded why a top engine like stockfish "accepts" to get into a position where the opponent can draw by 3 fold repetition with forced King's check. Is it unavoidable ? Is this took into account enough to discard certain moves from others within its evaluation ?
I am just asking.

Because SF prefers 0.00 over -0.01.

[syzygy]

If SF always search for opponent's possible checks to its king's in say next n moves we can then assume that when a 3 repetition by forced checks occurs SF is never taken by surprise then ?

Yes. Stockfish knows that this will be draw through repetition. In particular, checks are extended in search so that Stockfish should see such lines already at relatively low search depths.

Ok. may be as i said telling SF the "difference" between a SURE draw by rule of repetition and an evaluated draw (other than egtb) could open a very tiny window of improvment even if i don't know how.

Please come back when you know how...

[Ras]

Because SF prefers 0.00 over -0.01.

With the standard contempt of 24, that would be preferring 0.00 over -0.25, no?

[Pi4Chess]

If you think that some move should be different then you should give a position and say what move stockfish played and what it should play based on your opinion.

I am just asking those who know how engines are coded why a top engine like stockfish "accepts" to get into a position where the opponent can draw by 3 fold repetition with forced King's check. Is it unavoidable ? Is this took into account enough to discard certain moves from others within its evaluation ?
I am just asking.

Because SF prefers 0.00 over -0.01.

How it chooses between 2 0.00 moves?