Syzygy and draw by repetition

[Michel]

Because you've had a repetition at all, it's indicative the engine has no clue how to progress by the 'natural' evaluation. You may as well just follow strict DTZ til the counter resets.

I guess agree with this principle. It does not seem to lead to bad DTZ behaviour (silly sacrifices).

[jwes]

If I understand correctly, using just DTZ for KRPk would typically result in:

Promote pawn to queen.
Sacrifice queen.
Mate with rook.

[kbhearn]

If I understand correctly, using just DTZ for KRPk would typically result in:

Promote pawn to queen.
Sacrifice queen.
Mate with rook.

It could. But why is there a repetition since last progress move in the history of a KRPk ending? (and note that after the pawn was pushed once it'd go back to assuming the engine's eval could guide it to a win unless the 50 move rule was encroaching or the engine repeated positions again).

Mostly you'd expect to see repetitions come up in endings like KQkrp where you have to make a sequence of zugzwangs to maneuvre the attacking king behind the pawn and the eval may not understand what progress is.

[Dirt]

If I understand correctly, using just DTZ for KRPk would typically result in:

Promote pawn to queen.
Sacrifice queen.
Mate with rook.

Probably not. To guarantee the strange play it has to be able to force the acceptance of the queen sacrifice, and that has to be faster than the mate. A queen sacrifice is much more likely in a KQBNk ending.