Author: Peter Kappler
Date: 10:13:49 10/23/99
Go up one level in this thread
On October 23, 1999 at 09:29:20, Manuel Monasterio wrote:
>On October 23, 1999 at 04:12:51, Peter Kappler wrote:
>
>>
>>I reached this position as Black in a blitz game tonight.
>>
>>8/1p6/5k1n/8/4P3/5P2/3K4/8 b - -
>>
>>My first thought: "Cool, I've reached a winning ending."
>>5-10 seconds later: "Hmmm, I actually have to play precisely."
>>2 moves later: "Geez, this looks really tough to win, now."
>>5 moves later: "Well, at least I can give up my knight and draw..."
>>
>>At first I was annoyed with myself, but after fiddling around with the position
>>very briefly with Genius 6 and Hiarcs 7.32, I'm not certain Black can win. Both
>>programs give big positive scores for Black, but I'm not sure they are
>>understanding the position completely.
>>
>>I'm too tired to do any real analysis tonight. My hope is that I'll wake up in
>>the morning, and find the answer posted here. :-)
>>
>>
>>--Peter
>
>Hi Peter, I am eager to help you on this, but excuse my ignorance, I don't
>understand the notation, could you tell me where can I find the translation into
>algebraic? Thanks
Hi Manuel,
The notation I used is called EPD (Extended Position Description) which is an
extension of a previous standard called FEN (Forsyth-Edwards Notation).
Unfortunately, I can't find the URL to the complete spec (and the entire
document is a bit large to post), but here's the significant info:
4.1: Piece placement data
The first field represents the placement of the pieces on the board.
The board contents are specified starting with the eighth rank and
ending with the first rank. For each rank, the squares are specified
from file a to file h. White pieces are identified by uppercase SAN
(Standard Algebraic Notation) piece letters ("PNBRQK") and black
pieces are identified by lowercase SAN piece letters ("pnbrqk").
Empty squares are represented by the digits one through eight; the
digit used represents the count of contiguous empty squares along a
rank. The contents of all eight squares on each rank must be
specified; therefore, the count of piece letters plus the sum of the
vacant square counts must always equal eight. The solidus character
"/" (forward slash) is used to separate data of adjacent ranks.
There is no leading or trailing solidus in the piece placement data;
hence there are exactly seven of solidus characters in the placement
field.
The piece placement data for the starting array is:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR
4.2: Active color
The second field represents the active color. A lower case "w" is
used if White is to move; a lower case "b" is used if Black is the
active player.
The piece placement and active color data for the starting array is:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w
4.3: Castling availability
The third field represents castling availability. This indicates
potential future castling that may or may not be possible at the
moment due to blocking pieces or enemy attacks. If there is no
castling availability for either side, the single character symbol
"-" is used. Otherwise, a combination of from one to four characters
are present. If White has kingside castling availability, the
uppercase letter "K" appears. If White has queenside castling
availability, the uppercase letter "Q" appears. If Black has
kingside castling availability, the lowercase letter "k" appears. If
Black has queenside castling availability, then the lowercase letter
"q" appears. Those letters which appear will be ordered first
uppercase before lowercase and second kingside before queenside.
There is no white space between the letters.
The piece placement, active color, and castling availability data for
the starting array is:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq
4.4: En passant target square
The fourth field is the en passant target square. If there is no en
passant target square then the single character symbol "-" appears.
If there is an en passant target square then is represented by a
lowercase file character (one of "abcdefgh") immediately followed by
a rank digit. Obviously, the rank digit will be "3" following a
white pawn double advance (Black is the active color) or else be the
digit "6" after a black pawn double advance (White being the active
color).
An en passant target square is given if and only if the last move was
a pawn advance of two squares. Therefore, an en passant target
square field may have a square name even if there is no pawn of the
opposing side that may immediately execute the en passant capture.
The piece placement, active color, castling availability, and en
passant target square data for the starting array is:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -
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