14

Although very unlikely, the starting position could be a forced win for black. This would mean it is a position of mutual zugzwang, in the strong sense that whoever moves first loses. Wikipedia (Link) refers to one such position as trébuchet. Such positions are rare, and it would be a big surprise if the starting position was one of them.

The starting position has another property: it is symmetric. White and black have exactly the same possible moves (when written in descriptive notation).

My question: Are there any symmetric positions that are known to be a mutual zugzwang?

Improve this question
  • 1
    Great question, thank you! Nit: I think the trebuchet is a specific example of full point Zugzwang (KPvKP) rather than a synonym for full point Zugzwang. – Laska Oct 11 '17 at 15:28
  • 2
    The trebuchet is symmetrical if you are playing on a 7x8 board! :D – Laska Oct 11 '17 at 15:29
  • 1
    @Laska I think maybe the wiki article has been updated and expanded since I asked this question. – Dag Oskar Madsen Oct 11 '17 at 19:49
21

You can easily construct many such positions. For instance:

4k3/8/3P1P/8/8/3p1p2/8/4K3 w - - 0 1

First to move loses - either by moving a king and allowing the opponent to promote or by losing one (and subsequently next) pawn.

Improve this answer
  • What about: Kd1 f2 Ke1 f1=Q Kxf1 d2 Ke1........ – OldBunny2800 Dec 2 '16 at 0:05
  • 7
    @OldBunny2800: Your king uses an invisibility cloak at Ke1 so the pawn at f2 can't see it? – user21820 Dec 2 '16 at 1:33
  • @user21820 ???? – OldBunny2800 Dec 2 '16 at 1:43
  • 2
    @OldBunny2800: Your suggestion in your comment is invalid because you moved the king into check. – user21820 Dec 2 '16 at 2:14
  • 1
    @user21820 ohhhh, my bad. – OldBunny2800 Dec 2 '16 at 3:04
5

In all The chess books I've read, "trébuchet" is actually one particular case of a full-point double-zugzwang: the minimalist one you can get, with only one pawn for each player:

8/8/8/3pK3/2kP4/8/8/8 w - - 0 1

This pattern can be translated to 30 different positions, with the black pawn on any square in the b7-g7-g3-b3 rectangle. Whoever is on move will lose.

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.