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Zugzwang (wikipedia.org)
132 points by vo2maxer on Dec 15, 2019 | hide | past | favorite | 43 comments



A great example I love showing people is Alpha Zero's infamous "Immortal Zugzwang Game" against Stockfish [0]. Stockfish gets utterly annihilated in a trap that seemingly springs out of nowhere, though of course the reality is that Alpha Zero was actually really in control the entire time.

[0] https://www.youtube.com/watch?v=lFXJWPhDsSY


This is insanely exciting. I am terrible at Chess, but I've watched thousands of games on Youtube over the last 10 years or so.

Optically and mechanically, this game feels so refreshing. After being exposed to this almost robotic way of playing at the top GM levels - standard openings, usually the novelty starts around move 12-16 and sometimes longer! It is difficult to describe the "style" of AlphaZero. The best way I can describe it is by comparing how intermediate players chess without being exposed to a lot of theory.

Amazing and exciting for Chess fans.


So the humans play more robotically than the robots.


"The problem is not computers thinking like people, it's people thinking like computers."

(I think I read this quotation dated back to the 1960s or 70s, attributed to one of usual suspects of that time, but cannot find search results for it now ...)


“The real danger is not that computers will begin to think like men, but that men will begin to think like computers.“

— Sydney J. Harris As quoted, without citation, in Howard W. Eves, Return to Mathematical Circles, (1988), 63.

https://todayinsci.com/H/Harris_Sydney/HarrisSydney-Quotatio...


This ought to be permanently posted at the op of every HN thread.


I remember seeing this and thinking that Stockfish didn’t have to retreat its queen into the h8 corner, it could have simply moved it to a1


Is a PGN available?


There's one in the description:

1. Nf3 Nf6 2. c4 b6 3. d4 e6 4. g3 Ba6 5. Qc2 c5 6. d5 exd5 7. cxd5 Bb7 8. Bg2 Nxd5 9. O-O Nc6 10. Rd1 Be7 11. Qf5 Nf6 12. e4 g6 13. Qf4 O-O 14. e5 Nh5 15. Qg4 Re8 16. Nc3 Qb8 17. Nd5 Bf8 18. Bf4 Qc8 19. h3 Ne7 20. Ne3 Bc6 21. Rd6 Ng7 22. Rf6 Qb7 23. Bh6 Nd5 24. Nxd5 Bxd5 25. Rd1 Ne6 26. Bxf8 Rxf8 27. Qh4 Bc6 28. Qh6 Rae8 29. Rd6 Bxf3 30. Bxf3 Qa6 31. h4 Qa5 32. Rd1 c4 33. Rd5 Qe1+ 34. Kg2 c3 35. bxc3 Qxc3 36. h5 Re7 37. Bd1 Qe1 38. Bb3 Rd8 39. Rf3 Qe4 40. Qd2 Qg4 41. Bd1 Qe4 42. h6 Nc7 43. Rd6 Ne6 44. Bb3 Qxe5 45. Rd5 Qh8 46. Qb4 Nc5 47. Rxc5 bxc5 48. Qh4 Rde8 49. Rf6 Rf8 50. Qf4 a5 51. g4 d5 52. Bxd5 Rd7 53. Bc4 a4 54. g5 a3 55. Qf3 Rc7 56. Qxa3 Qxf6 57. gxf6 Rfc8 58. Qd3 Rf8 59. Qd6 Rfc8 60. a4


In German language, the word Zugzwang is also often used figuratively to describe a situation in which you are forced to take (unwanted) action due to external circumstances.

Example from recent news: Most online shops offer Black Friday deals. The ones that don‘t are „under Zugzwang“ to join them.


I know this is an English forum, but for this German learner, could you write out the whole example sentence? (I’d mostly like to see which preposition is used. My dictionary says “jmnd. _in_ Zugzwang bringen” but your sentence has a different usage.)


Both work. "Die Black Friday Deals bringen andere Händler in Zugzwang" or "Durch die Black Friday Angebote der großen Händler stehen auch kleinere unter Zugzwang"


"Ich stand unter Zugzwang" is just as correct as "Das neue Produkt der Konkurrenz bringt uns in Zugzwang", although being "under" Zugzwang sounds more common to me. You could also say "Das Produkt sorgt für Zugzwang".


"Unter Zugzwang stehen" and "in Zugzwang bringen" both sound natural to me, but "für Zugzwang sorgen" doesn't. (It's not incorrect, but it's not a common combination.)

Source: Am a native German speaker.


Die meisten Online-Shops bieten Black-Friday-Rabatte an. Diejenigen, die das nicht tun, sind unter Zugzwang, sich ihnen anzuschließen.


Another German named situation is zwischenzug, which is an intermediate move.

If your opponent makes a threat against your piece, instead of making the expected move to block, move, capture, etc; you can instead temporarily threaten one of your opponent's pieces elsewhere as long as it has a greater value, this forces your opponent to suddenly act defensively to protect their piece, which if exploited correctly can put you in a better position. You will still have to answer your opponent's original attack and defend your original piece but now you have some extra compensation.

Basically you are exploiting the fact that your opponent thought they had played a forcing move and so they probably didn't consider the effect on other parts of the board.


And if the Zwischenzug is a move that puts a piece somewhere where it can be easily captured (perhaps because it could already be, or because there are already lots of pieces attacked and the opponent can only take one at a time) then it is called a _desperado_.


I think Intermezzo is also used for that situation, as least here in England. We use a mix of German, French and Italian names for various situations.


Huh, didn't know there was a name for this. This is one of my go-to strategies in Chess, and I thought it was just a tactic people would use. Chess is such a studied game that I suspect almost all tactics have names by now!


Another interesting zugzwang situation is the game of animal shōgi [0], a simplified shōgi game that is strongly solved and found to be zugzwang position from the start.

[0]: https://en.m.wikipedia.org/wiki/Dōbutsu_shōgi


Sometimes people struggle to understand that chess may very well be solved as a win for black. This is a great illustration of that.


I'm a big fan of many Michael Brough games like Imbroglio, 868-HACK, and Cinco Paus because of how well he incorporates zugzwang into his designs. They always end up being these tiny, delightful challenges.


For German learners: It‘s a compound word. In German, and in English to some extent, you can join words to create a new word, e.g. Abstimmungsbekanntmachung (election notice).


To elaborate: Zug is move (the noun) and Zwang means coercion or force. So being in Zugzwang is means being in a situation where one is forced to move.


If it's move (the noun) rather than move (the verb) then wouldn't it be more accurate to say it means being in a situation where one's move is forced? (ie. the specific move is forced, rather than just being forced to make some move)


>the specific move is forced, rather than just being forced to make some move

Thinking about this gives me headaches;-) From a language perspective I think it could be interpreted both ways, a specific move or any move. The reason I chose the latter explanation is that it fit's with the real meaning of the word:

> one player is put at a disadvantage because they must make a move when they would prefer to pass and not move.[1]

The point is that the player is at a disadvantage because they have to move at all and not because they are forced to make a specific move.

[1] https://en.wikipedia.org/wiki/Zugzwang


Here’s a game which ends with a Zugzwang:

https://www.chessgames.com/perl/chessgame?gid=1008255 (future world champion Botvinnik vs Thomas; Nottingham 1936)

In the game, at the end, black is now, because of Zugzwang, forced to advance and weaken his f pawn. In a chess variant where players could pass instead of moving, it would be drawn, but since black must move, it is won for white.

White now simply has to move his king across the board, use it to take the now unprotected f pawn, then use the knight and king to take black’s b pawn, then promote one of his pawns to checkmate the black king.

Black wisely resigned.


I've played a lot of Hearthstone over the years and it has a concept similar to putting someone in check in Chess: Reducing their health to where one or two hits can kill them. Minions in Hearthstone can attack the opponent's minions or the opponent themselves - and most decks try to do the former efficiently (value-trade) and only attack (the opponent's) 'face' if they can't (either because all enemy minions are gone or there are no good trades to be had). The reason for this is that each player starts with a pretty big pool of health, so bringing that down to 0 must be a long term goal and going for that too greedily will cause you to lose board control and never get there. Only the most aggressive decks break this rule ('face is the place' goes the aggro motto). But interestingly one of the skills of the best players when playing slower decks is to know when to 'break character' and just go for 'face damage' instead even if it only puts the opponent low on health rather than outright killing them. At that point, the opponent is forced to make any trade they can in order to protect the little life they have left - they are in check. You 'reframe the conversation' by putting your opponent on their back heel.

Anyways, reading about Zugzwang made me wonder if there is a similar concept in Hearthstone too. And coincidentally, the latest expansion comes with a card that kinda fits the bill [1]. It generates powerful minions for you whenever you take damage, but is itself a minion with a lot of health, so it's hard to take down. When played against an aggressive deck with a lot of small minions, they get the choice of 1) Doing what they normally would do - attack your face - resulting in building you an army that would win you the game in a turn our two 2) Trading into the big minion to try to get rid of it - these are very inefficient trades and likely to not even succeed this turn or 3) Do nothing - which is probably the last thing they want to do, as the window of opportunity for an aggro deck to win gets smaller over time.

Obviously having this as a specific card isn't as elegant as the way this can be generated from the existing rules with a specific board state in chess, but I find it interesting to see how many of these more advanced game concepts can be put into a more casual game.

[1] https://hearthstone.gamepedia.com/Zzeraku_the_Warped


Zugzwang does not exist in Hearthstone, doing nothing is always a rule-compliant option.


You can construct a cool game out of non-transitive dice that does this on the very first move but in a completely counter-intuitive way.

https://en.wikipedia.org/wiki/Nontransitive_dice


An extremely rare zugzwang with 10 pieces +kings and pawns on the board. https://en.wikipedia.org/wiki/Immortal_Zugzwang_Game


Poker has the concept of positional advantage. Acting later is an advantage because you gain more information from your opponent. Although chess is a total information game and doesn't have this phenomenon, the player at turn can still be at a disadvantage due to circumstance.


May be it is not a coincidence that this word came up in one of the episode in season 4 of Billions[0].

[0]: https://en.wikipedia.org/wiki/Billions_(TV_series)


And from that we can conclude that when someone has nothing to lose (and/or nothing they expect or hope to win) - one can not be “in Zugzwang”. That is, they might be moving, but their situation can not get worse.


Well, a position with say a bare king and against a king and a rook is only lost because of zugzwang. If it was an option to pass, the side with the rook would not be able to force checkmate.


I wasn’t thinking specifically about chess, more broadly about life. For example in the case you presented the side with the bare king is not “in Zugzwang” cause his position can’t get worse. See, right now they are stuck in this useless position, but once the other side forces a checkmate they can finally end the stupid game and go home do something enjoyable...


The game of Go played on a 2x1 board apparears to be zugzwang right from the start, where any first move played is bad, due to the ko rule.

Since Go allows passing it's not a real zugzwang though...


Zugswang happens in software too: when your software project is done but people think it is dead because it has not been updated in 18 months...


Can't situations like that be solved with a sentence in the readme (without moving into a worse situation)?

"This software is feature-complete, it works well for its intended purpose. And if you were to experience a bug, someone will read your bug report." … or something like that.


Do people do that really?

Most of the time when I think a project is dead: Docker image for the project hadn’t been updated in years; many issues of Github with no replies?


This comes up in The Yiddish Policeman's Union by Chabon, an unique noirish alternate history dealing with chess and culture, among other things.


Zugzwang doesn't appear in Go game that often as in chess, even though it's much more complex game.


Americans call this up shit Creek without a paddle




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