Zugzwang is a German compound made of the nouns Zug (move) and Zwang (compulsion). Especially in (western) chess it describes the situation in which one player desperately would like to pass, but is forced to move by the rules.
Normally there is no Zugzwang in Go, however see no-pass go (forced to act vs. forced to move).
helopticor?: What about this example from Mathematical Go?
If white moves first, they get behind by three. If black moves first, they get ahead by only two. Both players want the other one to go first.
ilan: Sounds like someone got confused. The correct analogy is mutual stalemate, not mutual zugzwang. In a stalemate, the king is safe where it is, but any move puts it it in check. If this is true for both sides it is analogous to a seki by replacing the word "king" with "group" and "check" with "atari."
ilan: Actually, the difference goes a little deeper. When I was playing chess (30 years ago!), I learned all the principles in books, and in one critical tournament game, I put all my pieces in what I thought was the best strategical place, and then realised that, not only did I have no clue what to do, but I had no clue about which move were even playable in this position. I then decided to completely change my study habits, and concentrate on developing intuition to find candidate moves. This was when I started getting good. I also started winning games in which my opponents had no clue why they lost. The best example was a game I played in the 1975 Canadian Junior Championships against Frank Wang, who was White :
1. d4 Nf6 2. Nf3 e6 3. e3 c5 4. Bd3 Nc6 5. c3 d5 6. Nbd2 Bd6 7. e4 cd 8. cd de 9. Ne4 Bb4 10. Bd2 O-O 11. O-O Bd2 12. Qd2
During this opening, I realised that White was the type of player who knew where to put his pieces in what would be considered their most active squares, but who may not know what to do next. With that in mind, I decided to pose this exact problem, so played a move which didn't do very much, but forced him to decide on some original plan of action (a high entropy move, as dicussed in Tom/Go musings):
12. ... Kh8
My conjecture proved correct, as he proceeded to completely self-destruct. This became known as the game in which I "zugzwanged Wang." The rest of the game is kind of ugly, but the point is that it is hard to imagine that moving your king into the corner in a quiet position could cause an immediate collapse.
13. Rac1 Nxd4 14. Rfd1 Nxf3 15. gxf3 Bd7 16. Qf4 Nd5 17. Qg3 Bc6 18. Kh1 h6 19. Rg1 Rg8 (again proving what a good move Kh8 was!) 20. Nd6 Qf6 21. Ne4 Qxb2 22. Rc4 Qa3 23. Nd6 Qd3 24. Nf7+ Kh7 25. Re4 g6 26. Nxh6 Nf6 27. Nxg8 Rxg8 28. Qh3+ Kg7 29. Qxe6 Qxf3+ 30. Rg2 Bxe4 31. Qe7+ Kh6 White resigns.
That was weird actually moving game pieces around when replaying the game. It's been a while since I've played anything but Go.
OK, that may sound like a digression, but the point is that in chess, at some point between the opening and middle game, you have to find a plan, or even a move, which is not necessarily easy. And in some situations, the best thing to do is nothing at all. On the other hand, in Go, there is always something going on, and it is easy to find some kind of useful move, even it is not the best one.
Kirk: I see a connection to go, at least for handicap games. When giving a handicap, I used to always try so hard to complicate things with contact plays, cross-cuts, etc, but black would often just get stronger and I would gain little. From that I have learned that it is often better to play a slow, solid move, just reinforcing my position for example, and let black commit to something. It is often the case that you can find a way to make black's move less meaningful -- overconcentrated for example. You are right that all moves have value, but weaker players rarely understand how to make their stones work together effectively in a whole-board sense. It seems white can take profit in gote and let black play a weak move which then gives white another target to exploit. Similar idea, anyway.
- Now I long for the rest of the game, ilan!
- Someone explain me "forced to act vs. forced to move". Don't get it.
- Thanks for the rest, ilan, I'll have a look.
- Concerning "quiet position": Kh8 threatens Nxd4 because sacrificing the Bishop at h7 is no option any more.
- Concerning the term: Inviting the opponent to take the initiativ isn't really Zugzwang. He could have answered Kh1, not?