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        riddles >> medium >> Identify the Chess Pieces
        
(Message started by: THUDandBLUNDER on Sep 15th, 2003, 8:49am)
Title: Identify the Chess Pieces
Post by THUDandBLUNDER on Sep 15th, 2003, 8:49am
In the diagram below, each different letter represents a different Black or White chess unit.

For each letter find which unit it represents. (As usual, White is playing up the board.)
Title: Re: Identify the Chess Pieces
Post by BNC on Sep 15th, 2003, 11:24pm
Mind clarifying for me -- Black pawn and white pawn -- are they represented by different letters?
Title: Re: Identify the Chess Pieces
Post by THUDandBLUNDER on Sep 16th, 2003, 1:19am
Black and White pawns, if any, are represented by different letters.  :)

(I have changed the original wording from 'chess piece' to 'chess unit'.)
Title: Re: Identify the Chess Pieces
Post by BNC on Sep 16th, 2003, 2:39am
This is probably wrong (I'm a really bad chess player), but here is my guess (if, by some off-chance it's true, I'll explain my reasoning):

::[hide]
A: Black knight
B: White pawn
C: White king
D: White knight
E: Black king

And the black knight at D3 just made his mate move.
[/hide]
::
Title: Re: Identify the Chess Pieces
Post by wowbagger on Sep 16th, 2003, 3:38am

on 09/16/03 at 02:39:23, BNC wrote:
This is probably wrong (I'm a really bad chess player)

Not that being a good chess player would be of much help... ;)


Quote:
but here is my guess

At first sight, I also came as far as your A's, B's, C and E.
After taking a closer look at you proposition, I claim that the position would be illegal. That's because [hide]before Black's move (which doesn't mate by the way: cxe3/exd3) White must have made a legal move. But which? It can't have been with the King or any Pawn, and all squares where the Knight could have come from are occupied[/hide]. So I guess a little more thought is needed.

Really intriguing riddle by the way, T&B! :)
Title: Re: Identify the Chess Pieces
Post by THUDandBLUNDER on Sep 17th, 2003, 4:05am
Your solution is correct, BNC. But some explanation of your method would have been nice.  :)


Quote:
After taking a closer look at you proposition, I claim that the position would be illegal.

That Sherlock Holmes book seems to be taking a long time to arrive, wowbagger.  :)  K on b1 to c1 is OK.

Part 2: Move the A on g1 to b1.
Title: Re: Identify the Chess Pieces
Post by wowbagger on Sep 17th, 2003, 5:13am

on 09/17/03 at 04:05:05, THUDandBLUNDER wrote:
That Sherlock Holmes book seems to be taking a long time to arrive, wowbagger.  :)

Well, I haven't ordered it yet. And I wouldn't have time to read it for the time being anyway.


Quote:
K on b1 to c1 is OK.

Silly me! :-[
*scolds himself for not having installed a browser that does not crash using javascript with this forum, leading to cumbersome search for appropriate smiley code*
Title: Re: Identify the Chess Pieces
Post by BNC on Sep 17th, 2003, 8:21am

on 09/17/03 at 04:05:05, THUDandBLUNDER wrote:
Your solution is correct, BNC. But some explanation of your method would have been nice.  :)


Hehe. All-righty now!

Start by counting the pieces:
7 A's, 7 B's, 1 each of C,D, and E
So the 2 kings must be C,D or E. D is exculded, because 2 kins can't be next to eachother, so we know C and E are the two kings.

Let's look at B now. What piece can it be. It can't be a rook, because it checkes either king, and it couldn't have just moved in, because it's blocked on line 3. It can't be a knight, because for either color, there are two night checking a king. The same is true for bishop, and ofcourse queens. Black pawns are excluded for the same reason, so we know: B=White Pawn

A now. A could be either a rook or a knight. Since A=rook would put one of the kings in a check prior to the last move, A must be a knight.
If A-knight and E-king are different in color, E would be in "double check", so color(E)=color(A).

For similar logic as before, D must be knight too. Since color(E) is taken by A, we get color(D)=color(C)

Giving colors to A,E and C,D was just a guess. I don't see a reason they can't be reveresed...
Title: Re: Identify the Chess Pieces
Post by wowbagger on Sep 17th, 2003, 8:46am
Well done, BNC.


on 09/17/03 at 08:21:43, BNC wrote:
A now. A could be either a rook or a knight. Since A=rook would put one of the kings in a check prior to the last move, A must be a knight.

Minor nitpick: A could also be a queen, but it's the same argument as with the rook of course.


Quote:
Giving colors to A,E and C,D was just a guess. I don't see a reason they can't be reveresed...

I do! ;D
There are [hide]too many A's to be compatible with the B's, or in other words: Only Black can have promoted five pawns to knights[/hide].
Title: Re: Identify the Chess Pieces
Post by BNC on Sep 17th, 2003, 1:49pm

on 09/17/03 at 08:46:47, wowbagger wrote:
I do! ;D
There are <hidden msg removed>.


Why, ofcourse... it was staring me in the face, and I didn't see it... My turn to  :-[
Title: Re: Identify the Chess Pieces
Post by THUDandBLUNDER on Sep 18th, 2003, 7:31am
How about Part 2?:

Same diagram, but with the A on g1 moved to b1
Title: Re: Identify the Chess Pieces
Post by wowbagger on Sep 18th, 2003, 8:46am

on 09/18/03 at 07:31:44, THUDandBLUNDER wrote:
How about Part 2?:

Same diagram, but with the A on g1 moved to b1


Well, the reasoning for B and C/D/E still stands, but [hide]if A were a black knight, C would have to be the white king (square e1 is in double check) and we have no legal last move for white. (I hope this time I'm right.)[/hide]
So A is [hide]a black rook or queen[/hide] and, consequently, C is [hide]the black king and E the white king[/hide].
The last move would have been [hide]by the black rook, capturing on f1[/hide]. Before that, [hide]a white rook could have moved from g1 to f1, so I don't see a restriction regarding the colour of piece D: it could be a black or white knight[/hide].
Title: Re: Identify the Chess Pieces
Post by THUDandBLUNDER on Sep 19th, 2003, 7:47am
:[hide]
That's strange! The Answer says that the capture Rxf1+ rules out D being a White knight!

But, like you, I don't see how.

After all, White has a legal previous move.
eg, Black checked on h1 with the rook, White moved N from g3 to f1, and then Black played Rxf1+.  
[/hide]


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