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 A chess puzzle I've seen a while ago Goto page 1, 2  Next
Author Message
Ctuchik
Daedalian Member

Posted: Tue Jan 29, 2008 1:15 am    Post subject: 1

Two chess players are in the middle of a game as one of them accidently knocks the white king off the board. They pick it up, but don't remember where it was standing.
It is black's turn and the board looks like this:

Which square is the white king on?

I have one more. Nothing special, just a checkmate problem:
White to move and eventually win:
Chuck
Daedalian Member

 Posted: Tue Jan 29, 2008 2:30 am    Post subject: 2 For the first one, C3.
Amb
Amb the Hitched.

 Posted: Tue Jan 29, 2008 2:40 am    Post subject: 3 Second 1, NC6, Black is forced to capture it because it can cause checkmate on its next turn otherwise. This in turn frees the pawn to reach the promotion row
Amb
Amb the Hitched.

 Posted: Tue Jan 29, 2008 2:41 am    Post subject: 4 [/rescind due to idiocy]
Coyote

 Posted: Tue Jan 29, 2008 9:26 am    Post subject: 5 For the second problem: 1. Na6 2. Nc7+ 3. Nb5 4. Ra8+ 5. Ra7 6. Nc7+ 7. Na6 8. Ra8+ 9. Nb8 10. Nc6+ 11. Nd8+ 12. Nxe6+ 13. Ng5# (Black moves not shown, since all he can do is move the king back and forth between e8 and f7) I liked this one--it takes quite a bit of work to reach the goal without accidentally stalemating black.
Ctuchik
Daedalian Member

 Posted: Tue Jan 29, 2008 1:49 pm    Post subject: 6 @Chuck: you should also prove/explain your answer!
Scurra
Daedalian Member

 Posted: Tue Jan 29, 2008 2:30 pm    Post subject: 7 For the first one - what the hell? They couldn't remember which square the White King was on?! I mean, I'm a dreadful player but I can generally remember where the pieces are... _________________ still Quiz Olympiad champion. Must get a life. New definitions: COFFEE - someone who is coughed upon
jbvntx*
Guest

 Posted: Tue Jan 29, 2008 4:59 pm    Post subject: 8 1st one: Black pawn on B4, White pawn on C2, White king on B3. Then Black Bishop to D3 puts White King in check. White moves pawn to C4. Black captures pawn en passant, two discovered checks. White king moves to C3, capturing black pawn. Very slick. I thought there must be a mistake for a while.
Zahariel
Daedalian Member

 Posted: Tue Jan 29, 2008 5:15 pm    Post subject: 9 Wow, jbvntx, even with the answer given in the first reply, I couldn't figure it out. En passant capture is officially the most confusing rule in this entire game. I never realized it could cause a double discovered check. That's just dizzying.
Zag
Tired of his old title

Posted: Tue Jan 29, 2008 5:17 pm    Post subject: 10

 Scurra wrote: For the first one - what the hell? They couldn't remember which square the White King was on?! I mean, I'm a dreadful player but I can generally remember where the pieces are...

Now, now, none of that. If you like, rather than the players forgetting, suppose they had stepped away and, while cleaning, you accidentally bumped the king and wanted to put it back where it went.
Scurra
Daedalian Member

 Posted: Tue Jan 29, 2008 7:59 pm    Post subject: 11 Fairy nuff. Mind you, if that had happened, then I'd still have been standing around with the White King in my hand staring at the board in bemusement when the players came back..._________________ still Quiz Olympiad champion. Must get a life. New definitions: COFFEE - someone who is coughed upon
Amb
Amb the Hitched.

 Posted: Tue Jan 29, 2008 10:40 pm    Post subject: 12 I thought en passant had to be used in the first 5 turns of the game?
ralphmerridew
Daedalian Member

 Posted: Tue Jan 29, 2008 11:00 pm    Post subject: 13 No; it has to be used immediately after the other player moves a pawn two squares.
Sumudu*
Guest

 Posted: Wed Jan 30, 2008 1:00 am    Post subject: 14 In fact it would be pretty unusual for the chance to come up within the first five moves.
Courk
Daedalian Member

 Posted: Wed Jan 30, 2008 1:22 am    Post subject: 15 How do you reason all that out in the first one, though?
groza528
No Place Like Home

 Posted: Wed Jan 30, 2008 1:39 am    Post subject: 16 Courk: It is black's turn and he is in check. White's last move could not have been the bishop because the only way it could possibly move to that spot is from along the same diagonal, meaning black would already have been in check. Therefore, white's last move must have been the king. The king must have been blocking the check, which means either c2 or b3. The white king could not possibly have been at c2 because it's impossible for the two kings to be adjacent, which means the white king just moved from b3. b3 is in doublecheck, and neither the black rook nor the black bishop could have moved to reveal the other, which means both attacks must have been blocked by other pieces immediately before b3 came into check. These two pieces must have been captured immediately before the position we see, which means the white king must have taken one of them. However, the white king obviously couldn't capture on b4 or c4 because it would put itself in check. Therefore, one of the two blocking pieces must have moved away from b4/c4 as black's last move, in order to be captured by the king. So we have two pieces on b4 and c4. On black's last move he had to move one of them away from b4/c4. He also had to capture the other one. The only way black could possibly have captured either b4/c4 without ending his turn on either of those squares is an en passant capture, b4xc4 e.p. Sorry, a bit lengthy, but hopefully clear.
Courk
Daedalian Member

 Posted: Wed Jan 30, 2008 1:44 am    Post subject: 17 Perfect, thank you!
Ctuchik
Daedalian Member

Posted: Wed Jan 30, 2008 3:00 am    Post subject: 18

Great job! You got everything right!

Here are two more!
I did not invent them, so I hope you don't know them already

How do you get to this position in 4 moves?

White to move and mate in 3:
Antrax
ESL Student

 Posted: Wed Jan 30, 2008 6:13 am    Post subject: 19 I believe the second one was already posted, but I really like it nonetheless._________________After years of disappointment with get rich quick schemes, I know I'm gonna get rich with this scheme. And quick!
mith
Pitbull of Truth

 Posted: Wed Jan 30, 2008 2:20 pm    Post subject: 20 I'm pretty sure I've seen the other as well, though maybe not on here (and it's a good one too).
jbvntx*
Guest

 Posted: Wed Jan 30, 2008 3:02 pm    Post subject: 21 2nd batch 1st problem: White's four moves take the knight from G1 to B8, capturing a Black knight. Black's four moves get the pawn out of the way and move the knight from G8 to B8, capturing the White knight. These are very different from the "mate in x moves" type puzzles. I like them.
Janko*
Guest

 Posted: Wed Jan 30, 2008 5:02 pm    Post subject: 22 If you like them you should check out Raymond Smullyan's excellent books of retro chess puzzles (Chess Mysteries of Sherlock Holmes/Arabian Knights). If memory serves, the first one in this thread was composed by Smullyan in his youth. Bear in mind that his first book starts off with puzzles like that as an introduction - they get much more challenging!
Trojan Horse
Daedalian Member

 Posted: Wed Jan 30, 2008 7:03 pm    Post subject: 23 2nd batch 2nd problem (I've never seen it before, BTW): 1. Ne6, threatening 2. Qc8#. Only three moves for Black avoid that mate: 1. ... Bf6 2. Qc8+ Bd8 3. Qxd8# 1. ... h6 2. f8=Q+ Kh7 3. Qe4# 1. ... h5 2. Ng5 any 3. f8=Q# Did I miss anything?
Scurra
Daedalian Member

 Posted: Wed Jan 30, 2008 7:51 pm    Post subject: 24 Oh wow. The answer to the first one of the second set is so obvious it's really hard to see. Very clever._________________ still Quiz Olympiad champion. Must get a life. New definitions: COFFEE - someone who is coughed upon
Ctuchik
Daedalian Member

Posted: Wed Jan 30, 2008 11:17 pm    Post subject: 25

 Trojan Horse wrote: Did I miss anything?

Yes, 2. f8=Q+ is not possible, because there's still a knight on that square
Daedalian Member

Posted: Wed Jan 30, 2008 11:22 pm    Post subject: 26

Ctuchik wrote:
 Trojan Horse wrote: Did I miss anything?

Yes, 2. f8=Q+ is not possible, because there's still a knight on that square

No, the Knight was the first move. The real problem with that continuation is that Qe4 isn't mate yet (black responds with g6).
Trojan Horse
Daedalian Member

 Posted: Wed Jan 30, 2008 11:50 pm    Post subject: 27 Indeed. Someone solve this already. If I keep thinking about this problem, I won't have time to prepare for my classes!
Daedalian Member

 Posted: Thu Jan 31, 2008 12:00 am    Post subject: 28 If you're really curious, I found the thread it was previously posted in: http://www.greylabyrinth.com/discussion/viewtopic.php?t=12159 lostdummy solved it at the time.
Zag
Tired of his old title

 Posted: Thu Jan 31, 2008 4:34 am    Post subject: 29 For the 2nd batch, first problem, are you sure it didn't say 5 moves? Anyway, here is my 5 move solution: 1. Nf3 Nh6 2. Nh4 Nf5 3. Nxf5 d5 4. Rg1 Bxf5 5. Rh1 Bc8 Whenever I think I have 'proof' that something can't be solved, I always end up eating my words. But here's my proof that it can't be done in 4: I am assuming that the white knight takes the black one, and then some other black piece takes the white knight and then returns to its starting position. I'm pretty sure that, if there is a flaw in my reasoning, this assumption is incorrect. 4 moves means a total of 8 half-moves It takes 5 half-moves for one knight to take another, from their starting positions (when they start on the same column -- it only takes a 4 half-moves for a knight to take the opposite one). Black must spend on half-move on the pawn. Black must also spend two half-moves taking the white knight and then returning whatever piece took it to its starting position. This totals 8 half-moves, so no other moves are possible. Since 3 of the 4 black half-moves are accounted for, the black knight can only make one move, and the white knight will have to spend 4 moves reaching and taking it. This poses two different problems: First, if the white knight is taking the black one on its 4th turn, then there isn't time left for another black piece to take it and return. Second, there is no place the black knight can reach in only one move which another black piece can reach and return from in two moves. Or maybe my initial assumption is wrong. Sigh.
thok*
Guest

Posted: Thu Jan 31, 2008 5:31 am    Post subject: 30

 Zag wrote: Or maybe my initial assumption is wrong. Sigh.

Indeed it is. The piece that captured the white knight is currently on the square where it made the capture and not on its starting square.

(Once you figure out how that can happen, the rest of the puzzle is easy.)
ralphmerridew
Daedalian Member

 Posted: Thu Jan 31, 2008 1:10 pm    Post subject: 31 Position 1 in 3 moves: Nh3 d5 Na3 BxN Nb1 Bc8 Position 1 in 4 moves: Nf3 d5 Ne5 Nf6 Nc6 Nd7 NxN NxN
groza528
No Place Like Home

 Posted: Thu Jan 31, 2008 3:11 pm    Post subject: 32 ralphmerridew: Your 3-move solution doesn't account for the absence of the g8 knight.
Ctuchik
Daedalian Member

Posted: Thu Jan 31, 2008 5:04 pm    Post subject: 33

Congrats on solving the puzzle

Here's another one:

Black has just moved Rf3. How does white win the game?
Zag
Tired of his old title

 Posted: Thu Jan 31, 2008 6:50 pm    Post subject: 34 Got one! 1. e3, Rxe3+ 2. c3, Rxc3+ 3. Ka2, Ra3+ 4. Kb1, Ra1+ 5, Kc2, Rc1+ 6. Kd3, Rc3+ 7. Ke2, Re3+ 8. Kf1, Re1+ 9. Kg2, Rg1+ 10. Kf3, Rxg3+ <-- critical move 11. Ke2, Re3+ 12. Kd1, Re1+ 13, Kc2, Rc1+ 14. Kb3, Rc3+ 15. Ka2, Ra3+ 16. RxR#
Zag
Tired of his old title

 Posted: Mon Feb 04, 2008 6:43 pm    Post subject: 35 Jeez. I get one of these, and suddenly everyone loses interest in the thread.
BraveHat
Last of the Daedalians

 Posted: Sun Feb 10, 2008 3:10 am    Post subject: 36 Nice job, Zag!!
Johny Fake
Daedalian Member

 Posted: Tue Jun 22, 2010 1:20 pm    Post subject: 37 Please excuse me if you've seen this before. (scroll down on the page)
Zag
Tired of his old title

 Posted: Tue Jun 22, 2010 3:52 pm    Post subject: 38 Have you a definitive answer? I'm inclined to say that black wins, but I could pretty easily be convinced.
Chuck
Daedalian Member

 Posted: Tue Jun 22, 2010 4:28 pm    Post subject: 39 Games that allow time travel into the past should have rules covering things like this.
jesternl
Yankee Doodle Dutchie

 Posted: Tue Jun 22, 2010 6:09 pm    Post subject: 40 Futility Closet, where I saw it first, has some great puzzles from time to time. A wonderful waste of time.Last edited by jesternl on Tue Jun 22, 2010 6:19 pm; edited 1 time in total
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