=pod


=head1 NAME

Chess - Glossary


=head1 SYNOPSIS

A glossary of chess terms.


=head1 DESCRIPTION


=head1 GLOSSARY

=over 4

=item active

A piece is active when it is able to participate in guards and attacks.

=item algebraic notation

A board location notation in which the ranks are numbered from 1 (white's home rank) to 8
(black's home rank), and the files are lettered from `a' (queen's rook's file) to `h'
(king's rook's file), and spaces are denoted by their file letter followed by their rank
number.

=item army

Collectively, a player's chessmen.

=item attack

TODO

=item back rank

The rank containing the king's home space.

=item backward

Toward the player's back rank.

See also: forward.

=item battery

Two or more pieces supporting each other on the same line.

=item bishop

A species of chessman. Due to the way it moves, it always remains on the same color space
as its home.

=item black

One of the two colors of chess spaces, pieces, and players.

See also: color, white.

=item board

The playing surface for the game. Comprised of an 8 by 8  square lattice of equal-sized
square spaces. The rows are called ranks, and the columns are called files. The spaces
are alternately black and white as one moves up a file, or across a rank. The space at
the intersection of the first rank and the first file (conventionally, the lower-left
space on the board) is black.

=item capture

When a piece is moved to a space occupied by an enemy chessman, the previous occupant is
captured, and removed from play.

=item castle

A special move involving the king and one of the rooks. Also, an informal alternate name
for a rook.

See: castle long, castle short, rook.

=item castle long

Castling involving the king's rook.

=item castle short

Castling involving the queen's rook.

=item castling on opposite wings

When one player castles short and the other castles long.

=item centerl

The four central spaces, at the intersection of ranks 4 and 5 and files
d and e.

=item check

A guard against the opposing king.

See also: checkmate, double check, exposed check.

=item checkmate

Trapping the opposing king. The word `mate' comes from a word meaning `to kill'.

See also: check, trap.

=item chessclock

The special clock used in timed chess games.

=item chessman, chessmen

The name given to the objects that are moved around on the board during a game of Chess.

=item clock

Short for chessclock.

See: chessclock.

=item color

Refers not to the actual color of things, but to the fact that there are two distinct kinds
of each, and these are given the names `black', and `white'.

See also: black, white.

=item combination

A sequence of forced moves leading to advantage.

=item correspondence chess

Chess played by postal or electronic mail.

=item demolition

Destruction of the pawn structure protecting the hostile king's by way of a sacrifice.

=item descriptive notation

See: English Descriptive Notation.

=item development

Moves that activate chessmen.

=item diagonal

The conceptual equivalent to a rank or file, but rotated 45 degrees. As ranks and files are
to rooks, diagonals are to bishops. The long diagonals are the two diagonals that connect
opposite corners of the board.

=item diagonal battery

A battery on a diagonal involving the queen and a bishop.

=item discovered check

TODO

=item double check

The piece that moves ends up guarding the king, but its movement also exposes check by another
piece as well.

See also: check, exposed check.

=item doubled pawns

Two pawns of the same color on the same file.

=item doubled rooks

A battery of two rooks.

=item draw

See: stalemate

=item I<en passant>

French for `in passing'. A special pawn capture rule.

=item I<en pris>

French for `in take'. When a chessman is threatened.

=item endgame

TODO

=item enemy

See: opponent.

=item English Descriptive Notation

An older notation where the files are referred to by side of the board (queen's or king's) along with
the type of piece on the home rank at the beginning of the game (rook, knight, bishop). The ranks
are referred to by the names 1 to 8 as with algebraic notation, but the counting is relative to the
home rank of the player. So, each space will have two names: one when referred to by black, and another
when referred to by white.

=item exchange

TODO

=item exposed check

When check is achieved indirectly. Most commonly, the piece that moves ends up in a position
such that it guards the enemy king. But, if instead, the piece that moves gets out of the way
so that some other piece guards the king, check has been exposed.

See also: check, double check.

=item I<fianchetto>

When a bishop moves from its home onto one of the long diagonals.

=item flag

The time forfeit indicator on the chessclock.

=item forced mate

A forcing sequence leading up to checkmate.

=item forced move

When there is only one legal move possible. For example, when the king is in check, and
there is only one way to remedy it. Sometimes also used to refer to a weaker
situation when there is only one ``good'' move. For example, when the Queen is threatened
and there is only one way to neutralize the threat.

=item forward

Toward the enemy's back rank.

See also: backward.

=item four-move checkmate

Another name for scholar's mate.

=item gambit

An opening involving a pawn sacrifice.

=item Gruenfeld Defense

TODO

=item Gruenfeld Gambit

A chessman sacrificed by Black in the Gruenfeld Defense.

=item guard

A piece guards an enemy piece when the enemy piece is in a space that could be reached by it in
the next move, without regard for the possibility that the piece under consideration may in
reality be pinned in its current location.

Also, a piece can guard a friendly piece so that if the guarded piece is captured, the
guarding piece can capture back.

See also: pin, threat.

=item half-open line

A line with no friendly pawn that does have an enemy pawn.

=item handicap

TODO.

=item home

The initial space of a piece.

=item invasion square

TODO

=item isolated pawn

A pawn which does not have any neighboring friendly pawns.

=item king

A species of chessman. The only one that may not be captured (because if it is not permitted
to even be guarded, much less threatened, and as soon as it is not possible to remove such
a guard or threat--called checkmate--the game is over).

=item kingside

On the half of the board containing the king's home. Files `e' to `h'.

See also: queenside.

=item knight

A species of chessman. The only one that can jump over other pieces.

=item Legall's Mate

A pattern that arises when one side sacrifices the Queen to checkmate with one bishop and
two knights.

=item line

A rank, file, or diagonal.

=item line segment

A contiguous portion of a line. Maximally, an entire line; minimally a single space.

=item I<luft>

A square left open in front of the king to prevent checkmate on the home
rank.

=item major pieces

Queens and rooks.

=item man

Short for chessman.

=item mate

From the Persion I<mat> (death).

See: checkmate.

=item material

Another name for chessmen.

=item mating attack

An attack that could leat to checkmate.

=item middlegame

TODO

=item minor pieces

Knights and bishops.

=item move

A white ply followed by a black ply. Sometimes used to refer to a ply itself, when the ply
is an occupation rather than a capture.

See also: ply, occupy.

=item neutralize

A guard or threat can be neutralized by one of three direct methods: (i) capture the
offending enemy piece; (ii) interpose another piece; or (iii) move the piece away to
a safe location. An indirect method is to create a greater threat for the opponent.

=item obstruction

TODO

=item occupy

When a ply results in a chessman ending up in a space that did not already contain an enemy
chessman, the piece occupies the space.

See also: capture.

=item open file

A file containing no pawns of either color.

=item open line

A line containing no pawns of either color.

=item open rank

A rank containing no pawns of either color.

=item opening

The first moves in the game, where the focus is usually on the development of the
pieces.

=item opponent

White is the opponent of black and I<vice-versa>.

=item passed pawn

A pawn for which its file is free of enemy pawns and the two neighboring files are free of 
enemy pawns forward of its rank. No longer can it be blocked or captured by enemy pawns
(unless another capture brings an enemy pawn onto one of these ranks).

=item pawn

A species of chessman. The pawn is the only chessman that moves and captures in distinct
ways.

=item pawn duo

Two friendly pawns in the same rank and neighboring files.

=item perpetual check

TODO

=item piece

A chessman that is not a pawn. Sometimes, the word `piece' is used in place of `chessman'.
Usually context makes it clear which is meant.

=item pin

A chessman is pinned when it is not legal for it to move from its current location. Usually
this is caused by an enemy piece being placed such that moving the chessman would expose the
king to a guard by the enemy.

Also used to refer to a weaker case when it is not desirable to lose the more valuable
piece behind it.

=item play

See ply.

=item ply

One play in a Chess game.

=item promotion

When a pawn reaches the back rank of the opponent, it is promoted to any other piece than
a pawn or king.

=item queen

A species of chessman.

=item queenside

On the half of the board containing the queen's home. Files `a' to `d'.

See also: kingside.

=item rook

A species of chessman. Can participate in castling with the king.

=item sacrifice

A purposeful loss of a chessman in the interest of gaining some other advantage.

=item safe

A square which is not guarded by the enemy.

=item scholar's mate

Mate in four moves using the queen and bishop. Also called scholar's mate and four-move checkmate.
One way it could be played is:

    1. e4     e5
    2. Bc4    h6?
    3. Qh5    a5??  Could also be 3. Qf3  ...
    4. Qxf7#

The particular moves of black are not important, just that they don't interfere with white's line
of play.

=item shepherd's mate

Another name for scholar's mate.

=item Sicilian Defence

An asymetrical answer to White's C<1. e4>. First played in Palermo in the
1500's.

=item space

A board location that may be empty or contain a single chessman.

=item square

See space.

=item stalemate

When the player to move has no legal move, but is not in check, it is stalemate.

TODO: Other ways: repetition, etc.

=item starting rank

See: home rank

=item tempo

TODO

=item tie

See: stalemate

=item time control

TODO: traditional, sudden-death

=item tournament

TODO

=item trap

A piece is trapped when it is threatened and the threat cannot be neutralized. Also, a series of
moves by one player leading to an unfavorable position for the opponent.

See also: neutralize.

=item turn

See move.

=item unblocked lines

A line segment containing no chessmen.


=item unit

Another name for a chessman.

=item variation

TODO

=item white

One of the two colors of chess spaces, pieces, and players.

See also: color, black.

=item win an exchange

When an enemy rook is captured at the loss of a knight or a bishop.

=item I<zeitnot>

German term for a situation in which a player has little time to consider his plies
due to time control.

=item I<zugzwang>

From the German `compulsion to move'. A player foregoes immediate capture of compensating
material for that just lost, and instead creates a larger threat the enemy must respond
to, eventually achieving material (and perhaps positional) compensation.

Also, when every possible move worsens one's position.

=item I<zwischenzug>

German for an in-between move.

=back


=head1 AUTHOR

Gregor N. Purdy (C<gregor@focusresearch.com>).


=head1 COPYRIGHT AND LICENSE

Copyright (C) 1999-2006 Gregor N. Purdy. All rights reserved.

This program is free software. You may redistribute and/or
modify it under the same terms as Perl iteself.

=cut

