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        riddles >> hard >> Beautiful chess puzzle
        
(Message started by: Stefan Kneifel on Sep 1^st, 2003, 1:09pm)

Title: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 1^st, 2003, 1:09pm

White moves and is able to enforce a draw. How does he do that, considering the fact that his position is actually lacking a queen, a knight and a pawn?

Title: Re: Beautiful chess puzzle
Post by Ulkesh on Sep 1^st, 2003, 5:04pm

Does white hold a gun to his opponent's head and then offer a draw?

Apart from that I have no ideas. I'll admit that I gave up quite quickly and have started a chess program working on the problem. There seems to be no obvious answer, to the program at least; it's analysed everything up to 12-ply, and gone through 4.2 billion positions. Maybe the answer is something too 'stupid' for a computer to do, but somehow forces a draw.

To those who might notice that I've been away for a while (like my sparring partner T&B ;) ), my exams went well, I've been mostly sitting back and relaxing during the holidays, and I'm (kind of) looking forward to starting my 3rd year of Physics at University!

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 1^st, 2003, 10:36pm

on 09/01/03 at 17:04:11, Ulkesh wrote:

Does white hold a gun to his opponent's head and then offer a draw?

Umm... I don't know if this would be compatible to the Geneva conventions :D

on 09/01/03 at 17:04:11, Ulkesh wrote:

Apart from that I have no ideas. I'll admit that I gave up quite quickly and have started a chess program working on the problem. There seems to be no obvious answer, to the program at least; it's analysed everything up to 12-ply, and gone through 4.2 billion positions. Maybe the answer is something too 'stupid' for a computer to do, but somehow forces a draw.

I think it's definitely nothing any computer program will be able to solve. (That's why I posted it in the "hard" forum ;))
Hint: Examine how the pieces got to the squares where they are.

on 09/01/03 at 17:04:11, Ulkesh wrote:

my exams went well

Congratulations! :)

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 3:55am

This is really strange. Black's threats seem to be overwhelming. It should be obvious that this position is not very probable to occur in a real game (according to current rules ;)), because [hide]Black still has all pieces, so very sophisticated manoeuvres are needed to arrive at White's Bb8, Rf8 and Nh8[/hide].

Considering the fact that Black's threats seem to be overwhelming, I agree with putting this in the "hard" section.

No progress on my part yet...

Title: Re: Beautiful chess puzzle
Post by Ulkesh on Sep 2^nd, 2003, 5:12am

It seems to me that white must invoke the three-fold repetition rule. I think an exhaustive retrograde analysis will reveal perhaps that a certain position has been reached twice before, and one of white's available moves is to repeat that position, thereby allowing him to enforce a draw...

I've no idea what that move could be at the moment, but I'll have a look :)

Title: Re: Beautiful chess puzzle
Post by towr on Sep 2^nd, 2003, 9:56am

? castling maybe

though not as his first move.. (first take out the black queen)

Title: Re: Beautiful chess puzzle
Post by towr on Sep 2^nd, 2003, 10:02am

on 09/01/03 at 22:36:07, Stefan Kneifel wrote:

I think it's definitely nothing any computer program will be able to solve. (That's why I posted it in the "hard" forum ;))

I've allways meant to program one that could do all these evil puzzles (also help-mate, doublemoves etc).

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 10:13am

on 09/02/03 at 05:12:46, Ulkesh wrote:

It seems to me that white must invoke the three-fold repetition rule.

That's generally impossible, since one cannot decide whether this position is on the board for the first or the second time.
But: think of other draw rules you could eventually claim ;)

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 10:15am

on 09/02/03 at 09:56:07, towr wrote:

(first take out the black queen)

And how do you think we can achieve that? ???

It has to be forced, otherwise Black has too many possibilities to check. So possibly Ulkesh's idea is the right one.

edit: Ok, so it's not about three times the same moves - although it could be, in my opinion.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 10:17am

on 09/02/03 at 10:02:18, towr wrote:

I've allways meant to program one that could do all these evil puzzles (also help-mate, doublemoves etc).

If you succeed to write a program which can solve this riddle, I'll propose you for the Nobel Prize. Honestly.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 10:20am

on 09/02/03 at 10:13:08, Stefan Kneifel wrote:

think of other draw rules you could eventually claim ;)

You're not insinuating to check whether both player's time has run out? ;-)

So it could have to do with the 50 moves rule.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 10:22am

on 09/02/03 at 10:17:35, Stefan Kneifel wrote:

If you succeed to write a program which can solve this riddle, I'll propose you for the Nobel Prize. Honestly.

Hm, which one? Peace? ;D

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 10:54am

on 09/02/03 at 10:22:19, wowbagger wrote:

Hm, which one? Peace? ;D

Hm... oh... it seems there is none for Computer Science... what a pity...
Ok I'll send you a big parcel with Swiss chocolate instead ;D

But back to the problem: Thudandblunder's thoughts are going in an interesting direction :D
but: the last move was surely not a5xb4 - can you see why?

Title: Re: Beautiful chess puzzle
Post by towr on Sep 2^nd, 2003, 10:58am

on 09/02/03 at 10:17:35, Stefan Kneifel wrote:

If you succeed to write a program which can solve this riddle, I'll propose you for the Nobel Prize. Honestly.

Well, once we know the answer it is simple to make a program that can give the answer, wether you can consider that solving is another question. But in general I think if it follows the rules of chess it can be solved by a program, as long as it knows the right tricks.

Title: Re: Beautiful chess puzzle
Post by towr on Sep 2^nd, 2003, 11:00am

on 09/02/03 at 10:15:20, wowbagger wrote:

And how do you think we can achieve that? ???

You can easily shove some pawn in between. At least you'll avoid a quick death, and loosing you're rook before castling. The queen doesn't have to be knocked off the board right away or anything.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 11:05am

on 09/02/03 at 11:00:37, towr wrote:

You can easily shove some pawn in between. At least you'll avoid a quick death, and loosing you're rook before castling. The queen doesn't have to be knocked off the board right away or anything.

1. c3 Qc3: 2. dc Rg2:+ 3. Kd1 Rf1#
and with 1. d4 death is even faster :(

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 11:25am

on 09/02/03 at 10:54:32, Stefan Kneifel wrote:

But back to the problem: Thudandblunder's thoughts are going in an interesting direction :D
but: the last move was surely not a5xb4 - can you see why?

Well, a piece on b4 couldn't have had checked Black, so he wouldn't have captured on b4, but on a1 instead.
So Black's last move was with his Queen or Bishop. At first glance, I'd guess -1. ... Qh7-g7

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 11:50am

on 09/02/03 at 11:25:53, wowbagger wrote:

Well, a piece on b4 couldn't have had checked Black, so he wouldn't have captured on b4, but on a1 instead.

Well, that's not the point. There were probably many silly moves made in order to reach this position :)
But: think of TaB's words about the sequence the three white pieces have been captured.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 2^nd, 2003, 12:10pm

on 09/02/03 at 11:50:28, Stefan Kneifel wrote:

There were probably many silly moves made in order to reach this position :)

If silly moves are allowed, it's next to impossible to reconstruct moves. :-/

Title: Re: Beautiful chess puzzle
Post by towr on Sep 2^nd, 2003, 12:22pm

on 09/02/03 at 11:05:44, Stefan Kneifel wrote:

1. c3 Qc3: 2. dc Rg2:+ 3. Kd1 Rf1#
and with 1. d4 death is even faster :(

I'm not really good at reading chess-notation, but can't we still castle?
Perhaps just a delay in execution, but the whole game of chess is delay in execution for one side..

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 2^nd, 2003, 1:26pm

on 09/02/03 at 12:22:14, towr wrote:

but can't we still castle?

Hint: That's the key question to the whole problem ;)
Problem: What to do against Qa1# (Queen to a1 and mate) ?

on 09/02/03 at 12:10:19, wowbagger wrote:

If silly moves are allowed, it's next to impossible to reconstruct moves.

Hm... I don't think so. The rules for retro-analysis in a chess puzzle tell you that you can assume that certain moves were made only if you can prove that they were made; no matter how silly they are, as long as they obey the chess rules.

Title: Re: Beautiful chess puzzle
Post by SWF on Sep 2^nd, 2003, 11:02pm

All three of the captures must have been made before the bishop arrived at g8. I am guessing that due to the complex sequence of moves required to arrive at this position, it can be shown that it has been 50 moves with no pawns moved since the third capture=draw.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Sep 3^rd, 2003, 1:53am

Quote:

If silly moves are allowed, it's next to impossible to reconstruct moves.

White has just played his 2nd silly move. How did the game go? :D

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Sep 3^rd, 2003, 2:56am

on 09/02/03 at 23:02:57, SWF wrote:

Happy proving ;)
I suggest to start with the question, which pawn move must have been the last one.

on 09/02/03 at 01:57:15, T&B wrote:

White to play. Can he win?

Sorry, I'm new here... but wouldn't it be better starting a new thread, if you have a new problem?

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Sep 3^rd, 2003, 3:37am

Quote:

Sorry, I'm new here... but wouldn't it be better starting a new thread, if you have a new problem?

Threads are often continued in this fashion with similar type puzzles.

But, as no one has replied, I will do as you suggest.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 3^rd, 2003, 4:13am

on 09/03/03 at 01:53:53, THUDandBLUNDER wrote:

White has just played his 2nd silly move. How did the game go? :D

Nice one, T&B!

How about this start of the game:
[hide]1. a4 a6
2. Nf3 a5
3. Ng1[/hide]
Or a variation of the same theme, of course.

Please note that I am cautious about wording and other circumstances. ;)

Title: Re: Beautiful chess puzzle
Post by wowbagger on Sep 3^rd, 2003, 4:20am

on 09/03/03 at 03:37:22, THUDandBLUNDER wrote:

Threads are often continued in this fashion with similar type puzzles.

This is true, but I'd say this tends to cause cross-posting and, thus, confusion. I prefer starting a new thread and posting a link in the "original" problem thread.

Quote:

But, as no one has replied, I will do as you suggest.

Considering the quote in Stefan's post, I guess this refers to Chess Endgame (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_medium;action=display;num=1062585979).

Title: Re: Beautiful chess puzzle
Post by Lightboxes on Sep 25^th, 2003, 11:50pm

Regarding the orginal puzzle:::[hide]
I was trying to count the minimum number of moves needed to get to the position, then I realized that it takes two of white's units to get the two pawns (f5 and g6) to where they are. But there is another pawn that needs a white unit located at b4. The only unit that could effectively be is a rook. You'll see in a minute.
*********************************
1. for white and 2. for black
L for left side of the board and R for right side.
Adult = Q,B,N,R ; Child = pawn
*********************************
So, I start with obviously a minimum number of moves:
*********************************
11 moves: Both white and black pawns.
03 moves 2.k
05 2.N R
04 1.B R
03 1.B L
02 2.N L
04 1.N R
06 2.B Top
07 2.R Bottom
04 2.R Top
___If white's last move is to castle, then this can be proven:
04 1.N started on the left (C1) to sacrifice to help 2.Pxg6
04 1.Q started on the left (D1) to sacrifice to help 2.Pxf5
07 1.R H1 to sacrifice at b4.
___That way the pawn at a2 moves all the way up taking up
05 moves leading to a promotion to a rook to move to f8.
===
69 obvious moves.
***
04 Actually, I guess the rook at h1 could have sacrificed at g6
03 1.N at b1 to sacrifice at b4.
-04 which makes it:
===
65 moves proven to a minimum SO FAR...but I could be wrong.

So from here, I will prove more moves that are forced to occur and subtract any that may be proven in a shorter number of moves.
Explanation for the promotion of a pawn into a rook helps to explain that the black P at b4 took an "adult" piece because the white pawn at a2 can not help. So once the adult piece is gone, the pawn at a2 moves up to bring the adult piece back.
P.S. I don't have ALL the pieces listed, so it should be somewhat easy to get to 99 moves moved.
Added
I was wrong about the rooks in general because I was picturing them going through that diagonal path between the white pawns, but they could go through the pawns instead if e2 pawn has not moved yet.
[/hide]:::

Title: Re: Beautiful chess puzzle
Post by Andreas Lindmark on Oct 1^st, 2003, 10:30am

Look at blacks bishop at g8. Am i the only one unable to figure out how it got there?

Title: Re: Beautiful chess puzzle
Post by Lightboxes on Oct 1^st, 2003, 2:00pm

Regarding g8:
Black's pawn from h7 killed two white units to go to f5. Then the black bishop moved in zig-zaggedly. Then the pawn at f7 moved "up" one space.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 1^st, 2003, 2:35pm

Quote:

Then the pawn at f7 moved "up" one space.

I think you mean g7.

Title: Re: Beautiful chess puzzle
Post by Andreas Lindmark on Oct 1^st, 2003, 2:46pm

on 10/01/03 at 14:00:31, Lightboxes wrote:

Regarding g8:
Black's pawn from h7 killed two white units to go to f5. Then the black bishop moved in zig-zaggedly. Then the pawn at f7 moved "up" one space.

True. I was too stuck thinking that the g7 pawn moved after the h7 pawn thereby blocking the way.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 1^st, 2003, 7:44pm

Quote:

I was trying to count the minimum number of moves needed to get to the position,

To claim a draw by the 50-move rule we must prove that 50 moves have been played
since the last capture or pawn move.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Oct 2^nd, 2003, 2:20am

on 10/01/03 at 19:44:00, THUDandBLUNDER wrote:

To claim a draw by the 50-move rule we must prove that 50 moves have been played
since the last capture or pawn move.

We all know that, don't we? :)
[hide]Are you trying to keep Lightboxes from pushing ahead with his investigation into the number of moves?[/hide]

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 2^nd, 2003, 2:53am

Quote:

We all know that, don't we?

Well, Lightboxes was calculating the number of moves necessary to arrive at the given position.
Rather, I think we should work out which was the last Black pawn move and then calculate how many moves must have been played since then.

Title: Re: Beautiful chess puzzle
Post by Lightboxes' Clone on Oct 2^nd, 2003, 9:17am

:P
50 rule nothing!
Bah humbug!

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 2^nd, 2003, 12:01pm

on 10/02/03 at 02:53:07, THUDandBLUNDER wrote:

Ooops so much answers, and I didn't reply... TB is almost right: since all captures were also pawn moves (only three captures), one can concentrate on the question, which pawn move (either white or black) was the last one.

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 2^nd, 2003, 10:56pm

on 09/02/03 at 23:02:57, SWF wrote:

I am guessing that due to the complex sequence of moves required to arrive at this position, it can be shown that it has been 50 moves with no pawns moved since the third capture=draw.

I checked the suggestion to use the 50 move rule, but the position can be reached only 14 moves after the last capture. Pieces are captured on moves 21, 36, and 46.

Edits shown in yellow to correct the error pointed out by ThudandBlunder

1. e2-e3 a7-a5
2. b2-b4 b8-c6
3. c1-b2 c6-d4
4. d1-g4 d4-f5
5. b4-b5 f5-h4
6. b2-d4 a8-a6
7. a2-a4 g8-f6
8. g1-f3 f6-d5
9. f3-e5 a6-c6
10. d4-b6 c6-c3
11. g4-b4 c3-b3
12. b1-c3 h4-f5
13. f1-d3 f5-h4
14. a1-a3 h4-g6
15. e1-e2 g6-h4
16. h1-a1 b3-b1
17. f2-f3 b1-f1
18. h2-h3 f1-f2(ch)
19. e2-e1 ~~f6-h5~~ d5-f6
20. b6-a7 ~~h5-f6~~ h8-g8
21. a7-b8 a5xb4
22. a4-a5 f6-e4
23. a5-a6 e4-f6
24. a6-a7 f6-d5
25. a7-a8(Q) d5-b6
26. a8-a6 b6-a8
27. a6-g6 b7-b6
28. d3-c4 c8-b7
29. c4-a2 b7-e4
30. c3-e2 e4-f5
31. e2-g3 f5-g4
32. a3-c3 d8-c8
33. c3-c4 c8-b7
34. a2-b3 b7-c6
35. b3-a4 c6-f6
36. g3-f5 h7xg6
36b. a1-a3 g8-h8
37. a3-a2 h8-h5
38. a2-a3 h5-g5
39. a3-a1 g4-h5
40. a1-b1 g5-g4
41. b1-a1 g4-d4
42. a1-c1 d4-d5
43. c4-g4 d5-d4
44. g4-g5 d4-g4
45. c1-a1 g6xf5
46. g5-g6 e8-d8
47. g6-h6 h5-g6
48. h6-h8 g6-h7
49. h8-g8 d8-c8
50. e5-g6 c8-b7
51. g6-h8 g7-g6
52. a1-b1 f8-h6
53. g8-f8 h6-f4
54. b1-c1 f4-h2
55. f3-f4 g4-g3
56. c1-a1 g3-f3
57. a1-a2 h2-g3
58. a2-a3 f6-g7
59. a3-a1 h7-g8

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 2^nd, 2003, 11:31pm

BNC, perhaps you have missed a move out.

8. g1-f3 f6-d5 (The Black king's knight is now at d5.)
9. f3-e5 a6-c6
10. d4-b6 c6-c3
11. g4-b4 c3-b3
12. b1-c3 h4-f5
13. f1-d3 f5-h4
14. a1-a3 h4-g6
15. e1-e2 g6-h4
16. h1-a1 b3-b1
17. f2-f3 b1-f1
18. h2-h3 f1-f2(ch)
19. e2-e1 f6-h5 (And it now appears magically at f6.)

Title: Re: Beautiful chess puzzle
Post by BNC on Oct 3^rd, 2003, 12:18am

on 10/02/03 at 23:31:01, THUDandBLUNDER wrote:

BNC, perhaps you have missed a move out.

I think you meant SWF... This is way beyond my chess capabilities.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 3^rd, 2003, 3:20am

Ok I have to give a further hint: With his first move in the given position, White proves that the position can't be reached by your moves... :)

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 3^rd, 2003, 4:38am

on 10/03/03 at 03:20:21, Stefan Kneifel wrote:

Ok I have to give a further hint: With his first move in the given position, White proves that the position can't be reached by your moves... :)

That move must be 1. 0-0-0 (castles queenside).

This would imply that the Black rooks must have got where they are via the g-file. So I think the idea is that White castles because the given position is still thus attainable. Hence the position requires more moves than 50 to arrive at since the last capture.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 3^rd, 2003, 7:08am

on 10/03/03 at 04:38:01, THUDandBLUNDER wrote:

That move must be 1. 0-0-0 (castles queenside).

;)

Ok now for the beautiful part:
1. What was the last pawn move?
2. How many moves does it minimally take to get from there to the given position?

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 3^rd, 2003, 6:09pm

on 10/02/03 at 23:31:01, THUDandBLUNDER wrote:

BNC, perhaps you have missed a move out.

Sorry about the error, but thank you for holding BNC responsible instead of me. That knight was making move wasting circles while positioning the white pieces, but I was careless in tracking its position. But it was easy to correct (the post above has been edited to fix).

The point I was trying to make is that that position is reachable in a way that white cannot force a draw. Now I see Stefan is saying white is able to castle, and then force a draw. From that board position there is no way of knowing that. One could just as easily say that white can force a draw by moving a1-a2 thus giving the same board position for the third time.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 3^rd, 2003, 9:43pm

Quote:

The point I was trying to make is that that position is reachable in a way that white cannot force a draw.

And well done for proving it. It must have taken quite some time and effort. I think the logic is:

Draw => 50-move rule must apply => White must still be able to castle.

(The last part is due to you.) :)

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 4^th, 2003, 9:10am

on 10/03/03 at 18:09:30, SWF wrote:

From that board position there is no way of knowing that.

Not from the position, but from general study rules (they say that you're always allowed to castle, unless one can prove that castling isn't possible any more).

Title: Re: Beautiful chess puzzle
Post by wowbagger on Oct 5^th, 2003, 11:44am

on 10/03/03 at 18:09:30, SWF wrote:

One could just as easily say that white can force a draw by moving a1-a2 thus giving the same board position for the third time.

That's an interesting point. If the given position is legal, so is the same position with a few queen/rook/bishop/knight moves repeated.

SWF, please use standard algebraic chess notation (http://www.wikipedia.org/wiki/Algebraic_chess_notation), if only to please me - and make me really consider your moves instead of just glancing at them.

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 5^th, 2003, 5:09pm

on 10/04/03 at 09:10:36, Stefan Kneifel wrote:

Not from the position, but from general study rules (they say that you're always allowed to castle, unless one can prove that castling isn't possible any more).

I would buy that if somebody can demonstrate castling is possible from that position. However, I am convinced that this position is not reachable in a way that would still permit castling:

Assuming the white king and queens's rook never moved (i.e. castling permitted), the knight at h4 must have moved there from f5 or g6 because there is a pawn at g2 the whole game, and moving from f3 would mean white ended a turn while in check. The black bishop at g3 can only move after pawns occupy f5 and g6. Therefore the h4 knight was there before that bishop ever moved. For the bishop to end up at g3, it must have arrived by having previously gone through either e3 or f4.

The white king's rook either ended up at f8 or was captured by a black pawn (in which case the f8 rook is a promoted white pawn). Either way, the h1 rook could not have gotten into position to reach f8 or be captured until white pawns are at e3 and f4 (e3 necessary for white king's bishop to get out of the way). By previous paragraph, e3 and f4 are occupied by pawns after there are black pawns at f5 and g6. This leaves no way for the white king's rook to have been captured, thus the rook at f8 is the white king's rook and not a promoted pawn.

Somehow that white rook has to get around the two black rooks with pawns already at e3, f4, f5, and g6. There is no way to do this. The only method with some hope is to not move the h2 pawn up until last and use h3 as a rook parking space while other rooks pass. However, the black bishop ruins any chance of that working.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 6^th, 2003, 2:08am

on 10/05/03 at 17:09:00, SWF wrote:

Somehow that white rook has to get around the two black rooks with pawns already at e3, f4, f5, and g6. There is no way to do this.

Congratulations, this is the crucial point! But: there is a way to get around the two black rooks: they can change their place at a2/b2/a3/b3...

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 6^th, 2003, 7:41pm

on 10/06/03 at 02:08:30, Stefan Kneifel wrote:

there is a way to get around the two black rooks: they can change their place at a2/b2/a3/b3...

I must be missing something. Is there a flaw in the reasoning of the previous post? I don't see how the white rook can get past the black king. I hope there isn't some strange rule unknown to me, like a white pawn can be promoted to a black knight.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 6^th, 2003, 8:08pm

Quote:

I don't see how the white rook can get past the black king.

Let White still be able to castle.
Let a White rook be at f1.
Let the Black rooks be at a2 and b2.
Let the Black bishop be at h2.
Let the Black queen be on d4.
Let the Black king be at f6 (via g7).

Then White can move his f1 rook to c3 via the 8th rank.
The Black rooks then take the same route (moving the other way) to get to f2 and f3.
The White rook on c3 moves to h6.
The Black king on f6 moves to b7 via 8th rank.
The White rook on h6 moves to f8.
The White queen on d4 moves to g7.
The Black bishop on h2 moves to g3.

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 6^th, 2003, 10:08pm

OK, T&B, I was able to follow your description and got the board position with white still able to castle. I wasted many moves, and exceeded the 50 move rule, but reducing to 49 moves after the last capture is within reason.

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Oct 7^th, 2003, 11:09am

on 10/06/03 at 22:08:37, SWF wrote:

but reducing to 49 moves after the last capture is within reason.

Hm... the shortest game I found to get to the position is the following ("---" means senseless waiting move):

Quote:

1. b4 a5 2. b5 Ra6 3. Nc3 Rc6 4. Nd5 Rc3 5. Ba3 Nc6 6. Bc5 Ne5 7. Nb4 ab
8. a4 Nc4 9. a5 Nb6 10. a6 Nh6 11. a7 Nf5 12. a8R Nh4 13. R8a6 Na8 14. Rg6 hg
15. Ba7 b6 16. e3 Rh6 17. Qf3 Bb7 18. Qf5 gf 19. Nh3 Rd6 20. Nf4 Bf3
21. Ng6 Bh5 22. Nh8 Bg6 23. Bc4 Bh7 24. Rf1 g6 25. h3 Bg7 26. --- Be5
27. --- Bh2 28. f4 R6d3 29. Rf3 Kf8 30. Rg3 Kg7 31. Rg5 Kf6 32. Rh5 Bg8
33. Rh7 Qc8 34. Rg7 Bh7 35. Rg8 Qb7 36. Rb8 Qe4 37. Rb7 Qe5 38. Bb8 ---
39. Rba7 --- 40. R7a2 Ra3 41. --- Ra7 42. --- Rb7 43. Ba7 Rb8 44. --- Rg8
45. --- Rg7 46. --- Bg8 47. --- Rh7 48. --- Rh5 49. --- Rg5 50. --- Rg3
51. --- Rf3 52. --- Rf2 53. --- Ra3 54. Bb8 Ra7 55. --- Rb7 56. Ba7 Rb8
57. --- Bh7 58. --- Rg8 59. Bb8 Rg7 60. Ra7 Bg8 61. Rb7 Rh7 62. Ba7 Rh5
63. Rb8 Bh7 64. Rg8 Rg5 65. Rg7 Bg8 66. Rh7 Rg3 67. Rh5 Kg7 68. Rh7+ Kf8
69. Rg7 Ke8 70. Bb3 Kd8 71. Ba4 Kc8 72. Bb8 Bh7 73. Rg8+ Kb7 74. Rf8 Bg8
75. --- Rgf3 76. --- Bg3 77. --- Qg7 78. O-O-O ½:½

what is exactly 50 moves after the last pawn move.

I hope it's correct... ;)

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 7^th, 2003, 7:53pm

Previously, I had been counting since the last capture not after last pawn move. In the sequence of moves I used, white's first move from that position is also exactly 50 moves after the last pawn was moved. Looks like doing it in fewer moves is not possible with that obstacle course the rooks must pass through. But a couple of days ago I thought there was no way for the rooks to cross paths, and I may be mistaken again.

Whoever invented this problem was quite clever.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 7^th, 2003, 9:17pm

Quote:

Whoever invented this problem was quite clever.

It is not the only one of its type.
Here is another, though I am not suggesting that you try to solve it.

White to play and draw.

Title: Re: Beautiful chess puzzle
Post by kofman2155 on Oct 8^th, 2003, 2:48pm

I'm sorry, I'm new here and this may come of wrong, but their is no answer to the first puzzle. Their is no way to enforce a draw, becuase of a double threat on mate. I'm a chess player myself and usually can see moves fairly fast. Not to say that a draw is impossible, it simply can not be forced.

http://www.ocf.berkeley.edu/~wwu/YaBBAttachments/chess.png

First their is the obvious threat. If Rook on f2 doesn't move. Queen to a1 is mate.

If u castle, that's mate. Say you through the queen away, it's still mate. h4-g2+ The knight can be sacrficed and used for mate. Unless u can find a move that blocks both threats, I see the game fairly hopeless. First off u have to block off the threat from the queen. You can either move the pawn to d4. Which than results in. f2-c2+ and than mate. Or you can move the rook, which is fatal, due to f2-g2+ and than mate. That is why I come to a conclusion that is is impossible to save yourself, yet alone draw. Also note that their is no way for white to check the king, and black will mate in one move if left alone.

No offense, I think it's cruel to make people think over things that can't be solved.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Oct 8^th, 2003, 4:45pm

Quote:

I'm sorry, I'm new here and this may come of wrong, but their is no answer to the first puzzle.

Try reading the thread before posting. :P

Quote:

No offense, I think it's cruel to make people think over things that can't be solved.

But it has been solved.

Title: Re: Beautiful chess puzzle
Post by kofman2155 on Oct 8^th, 2003, 7:34pm

I'm sorry, I'm confused and still disagree. Just tell me what move should white make to save itself. I've read a few answers, while still confused (seems like people are trying to derive on how, they got to that position instead of answering the initial question of how does white enforce a draw). My answer remains it can't. Please point me to the move that white should make in order to draw (just it's first move, if it the king can walk away from this position, than I'll consider the posibility for a draw), if you can walk away from this, than the person who solved it should be a GM.

----------
I think I finally get it, the game is a draw becuase 50 moves have went on prior to getting into that position. Let's say that's the case, I do believe there are still exceptions to this rule, and a piece will be take with black's next move breaking the 50 move streak unless you somehow prove that no pieces have been taken prior to white's 50th move, which is impossible and unlikly considering all the weakness, unless ofcoarse once again the two openents played perposily this way to stretch the game for 50 moves. Please explain the answer to me, if there is one. I still strongly disagree becuase it goes against everything I know as a chess player

Title: Re: Beautiful chess puzzle
Post by SWF on Oct 8^th, 2003, 9:00pm

on 10/08/03 at 19:34:19, kofman2155 wrote:

I do believe there are still exceptions to this rule, and a piece will be take with black's next move breaking the 50 move streak

Black has already made 50 moves since the last pawn was moved. When white moves without making a capture, that makes 50 moves for each side since the last pawn move or capture.

Title: Re: Beautiful chess puzzle
Post by wowbagger on Oct 9^th, 2003, 3:40am

on 10/08/03 at 19:34:19, kofman2155 wrote:

I still strongly disagree becuase it goes against everything I know as a chess player

Being a chess player myself, I understand your unease very well. In fact, I had the same problem with these retro puzzles at first. Maybe reading this post (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_easy;num=1062651593;start=0#11) by THUDandBLUNDER helps.

Title: Re: Beautiful chess puzzle
Post by cryptreaper on Jun 30^th, 2004, 7:49pm

http://www.ocf.berkeley.edu/~wwu/YaBBAttachments/chess.png

Okay,from what kofman2155 said I found a way to block the queen threat and the horse and rook threat.Simply stay where you are and move c2-c3,that blocks the queen and if b4-c3 then it will take away the chance for the queen to take the checkmate in a few moves.That enables you one turn,because you could either take the pawn and the queen goes for the checkmate,or you can leave the pawn and let it take you,you buy yourself a turn.
The horse and rook situation,if you just stay there and n-g2,
you must move back,if he pushes the r-f1,then you move k-e2
thus gaining you some turns to escape and run,I think the drawing situation concerns your king running away and drawing with the other king.
Ok once you have gained the king advantage by the horse (if he does it this way) move the b-b3,then if he takes the rook,you move b-f7,then if he takes you,you move n-f8,one careless move and he gets a checkmate.So he has to keep his queen at that position,thus saving the rook for later deeds.
Now the stress is all on the black king because if he doesen't do something it's a checkmate.So his only choice is to move the r-e3 thus protected by the knight and checking the king.So his only choice is to move to k-c4.Then black moves e7-e5,thus checking the king again,all he can do is k-e5.

Booyaaaaaaaa I'm going to post the rest later when I have a break in my genius tactics,and if someone can do the rest for me later,that'll be fine!

Title: Re: Beautiful chess puzzle
Post by cryptreaper on Jun 30^th, 2004, 9:06pm

http://www.ocf.berkeley.edu/~wwu/YaBBAttachments/chess.png

Back to what I was getting to.Blacks move -c6 checking the king,his only move is to move back k-c4.Then black moves -b5
taking out the winning pawn for white.White moves his king to take out the pawn.In one move white is going to win so it is time to take out the white rook with the black rook(r-a1).It is time,white moves the only horse they have to f7 (n-f7).In one move it will be checkmate for white so black has to move the bishop or the rook moves to check the king.

Rook moves to check the king is the best idea so thats what black does,king moves to c4 (k-c4) thus blocking the bishop.Then black attacks the horse with the bishop.Rook has to take the bishop.Then the queen takes out the rook at f7.Check again,so the king goes to d4.If the queen doesen't move then it will get taken out,so it moves itself into a check against the white king.(Q-f6).Then the King is under check and must move back to the original spot.So the queen checks it again and the king must move,take note without the black queen it is mostly impossible to win for black.So the black queen checks the king again,and it moves back to its original spot.The queen checks the king again,with the same result,if the black queen didn't check the white king then the white pawn on d2 would take out the rook,so the queen checks the white king again and its all over!3 times the same thing its over!
(PS this is not the right answer I was just too lazy to type it all,oh yeah the post before this has all the good information.)

Title: Re: Beautiful chess puzzle
Post by Stefan Kneifel on Jul 1^st, 2004, 12:15am

on 06/30/04 at 19:49:02, cryptreaper wrote:

Simply stay where you are and move c2-c3,that blocks the queen

No it doesn't - Qxc3 does the job...

Title: Re: Beautiful chess puzzle
Post by cryptreaper on Jul 1^st, 2004, 6:44am

on 07/01/04 at 00:15:15, Stefan Kneifel wrote:

No it doesn't - Qxc3 does the job...

No it doesen't,if it takes c3 then you take -c3 it and it takes you with the pawn -c3 and you move K-D1.This leaving the bishop at G8 defenceless and the knight at h8 can just checkmate.

Title: Re: Beautiful chess puzzle
Post by THUDandBLUNDER on Jul 2^nd, 2004, 7:57pm

on 10/08/03 at 21:00:13, SWF wrote:

Black has already made 50 moves since the last pawn was moved. When white moves without making a capture, that makes 50 moves for each side since the last pawn move or capture.

So White can make any non-capturing piece move, right? For example, Rb1.
That makes 50 moves and he can claim a draw.
Therefore he doesn't need to still be able to castle, does he?
Or am I missing something?

Title: Re: Beautiful chess puzzle
Post by Hippo on Mar 19^th, 2007, 8:49am

I am not sure the formulation of the problem was OK ... should not it be ... "There can be played a move in this position and if you play that move its draw." ... In that case 0-0-0 is the answer ... it can be played in the position and if played, the game ends by 50move rule draw.
There was proved that if rooking is possible ...

I don't think it was proven the 50move rule draw is forced if the rooking is not possible so other move didn't force the 50move rule draw.

If I look wrongly and the 50move rule draw is almost forced you cannot move pawn nor capture a piece.

Title: Re: Beautiful chess puzzle
Post by rmsgrey on Mar 19^th, 2007, 9:19am

on 07/02/04 at 19:57:22, THUDandBLUNDER wrote:

If white castles, that "proves" that the king (and the castling rook) have been in place all game. In order to shuffle the other pieces into place without moving the white king (or rook) out of the way, it seems that 49.5 moves must have passed since the last pawn move/capture. If white doesn't castle, then there are shorter possible histories, so you can't "prove" that it's a draw...

The deciding factor in such puzzles appears to be what a passing expert player could deduce with certainty by watching the game from the given position on - so if white doesn't capture, castle, or move a pawn on the first turn, he would be unable to castle later (the game continuing would "prove" that it wasn't a 50-move draw, so white must not be able to castle). Contrariwise, if white does castle, that proves it's a draw because the only history that allows him to makes it the 50th move.