Glossary of Chess Expressions

Artificial Castling

Artificial castling is an attempt by a player who is unable to castle by normal means of trying to get his king out of the centre and into the castled position. Normally it involves moving the f-pawn one square, moving the king where the pawn was, moving the rook and then putting the king on th g-file.


The Centre means the four squares d4, d5, e4 and e5. In the Opening of the game, it is normally important to control the Centre. Most chess openings involve placing at least one pawn in the Centre and trying to control the centre with the knights and the bishops. Knights, Bishops and Queens can be much more valuable if they are placed close to the Centre than they are if they are placed near the edge of the board.

Clearance sacrifice

This is a sacrifice, usually of a pawn, removing it from a critical square and allowing another piece to move in.


Development is the act of getting the pieces off the starting squares and bringing them into the game. The act of developing pieces is vitally important in the early part of the game, as important to a chess player as it is to a football manager to make sure that all of his players find their way out of the changing room and onto the pitch.


Discovery is the ability of one piece to move out of the path of another so that the second piece creates a threat.

White's pawn moves forward to the e6 square. This discovers an attack on the Black king from White's Bishop, while the pawn threatens Black's queen. Black must spen his next move getting out of check whereupon White captures the Black queen



Flight Squares

A Flight Square is a piece's escape route when it is attacked. Usually we use the expression "flight square" when we are looking for an escape route for our king.

Forced move

A forced move is a move which has a very limited number of replies which do not immediately lose. There will be some kind of threat involved which the opponent simply cannot ignore.


Hiarcs is a computer program which analyses chess positions and suggests lines of play.

Isolated Pawn

An isolated pawn has no pawns on the files on either side. It can never be protected by other pawns, so if it is attacked it must be defended by pieces.

Material advantage

A player who has a greater value of pieces that the opponent has a material advantage. A Queen is worth 9 points, a rook 5, knight and bishop 3 each, a pawn 1.


Mobility is a piece's ability to move freely. It is normally dependant upon pawns and how many of them get in the way of the long-range pieces.

Positional Play

Positional play is play based upon general considerations rather than precise tactical threats. A move is considered to be positional when the decision to put a piece on a particular square is based upon the long term view rather than the short term.

Open File

An Open File is a file which does not have any pawns on it. It is usually a good idea to place your rooks on open files because they can quickly move into your opponent's half of the board where they create a lot of threats.


Overloading is a situation where one piece is being asked to do too much work. Look at the following diagram:-

In this situation the Black queen is overloaded. She is protecting the Black rook from the attack by the White Queen, but more importantly she protects the Black King from a Back Rank Mate. White, to play, would capture the rook as, although White would lose a queen (9 points) for a Rook (5 point) White's rook would then deliver a deadly check from c8.


Passed Pawn

A Passed Pawn is a pawn which cannot be stopped by an enemy pawn, either by capturing or blockading. Look at the following diagram.

The White pawn on d4 is a Passed Pawn. It can only be stopped by Black's king. All the other pawns in this diagram are blockaded by enemy pawns. In practice, this position will be an easy win for White because his passed pawn will keep Black's king tied down and White's king will then be able to make his way to a5, capture the Black pawn there and then White will have another passed pawn on the a-file.


A plan is your intended course for the rest of the game. There are as many different plans as there are chess positions and experience will suggest to you what you should be doing in a particular situation. To find a plan you should look for weaknesses in your position and that of your opponent, and then try to work out a sequence of moves which will take advantage of your opponent's weaknesses without letting him take advantage of yours.


Promotion of a Pawn happens when that pawn reaches the other end of the board, so for a White pawn this happens on the 8th rank, for a Black pawn it happens on the first rank. A pawn may promote to a Queen or a Rook or a Bishop or a Knight, even if you already have your original pieces of the type you select. In theory, you could have up to 9 queens on the board at once (if you kept your original queen and promoted every pawn), but you would become very confused! Two queens is normally more than enough to win.

Look at this diagram:-

White's pawn is on the 7th rank and it is White to play. Click on the Pawn.

Pawns are the only chessmen which are allowed to promote to other pieces.


Waiting Move

In many endings, we reach a position in which we cannot make progress because our opponent's king occupies the square we want, but it is the wrong side to move. A Waiting Move is just that - a move which does nothing towards our plan other than change whose turn it is.

Click on your Browser's "Back" button to return to where you were.
Return to Coaching Index
Return to PWCC Home Page