Glossary

A

Active King — A king that participates in attack or defense, not hiding passively.

B

Bad Bishop — A bishop blocked by its own pawns on the same color squares.

Bishop Pair — Two bishops working together — a lasting advantage in open positions with play on both wings.

Blockade — Stopping a passed pawn by placing a piece directly in front of it. Knights are ideal blockaders because they can attack the pawn while remaining stable.

Breakthrough — A pawn sacrifice that clears a path so another pawn can promote.

Building a Bridge — The Lucena technique of using the rook to block checks.

C

Checking Distance — The space a rook or queen needs between itself and the enemy king to keep giving effective checks; too short a distance lets the king escape.

Connected Passed Pawns — Two or more passed pawns on adjacent files that defend each other as they advance.

Corresponding Squares — Squares where kings must be positioned relative to each other.

Cut Off — Using a rook to restrict the enemy king by file or rank.

D

Distant Opposition — Opposition with 3, 5, or 7 squares between kings.

F

Fifty-Move Rule — A game is drawn if 50 consecutive moves pass with no pawn move and no capture. Important in endgames because many theoretical wins require more than 50 moves without a capture.

Fortress — A defensive position that cannot be broken despite material disadvantage.

K

Key Squares — Squares that guarantee pawn promotion if the attacking king reaches them.

L

Lucena Position — The winning R+P vs R position with pawn on 7th rank.

M

Minority Attack — Advancing a smaller pawn group against a larger one to create a weakness, often used in pawn-majority and same-side-pawn endgames.

O

Opposite-Coloured Bishops — Bishops travelling on opposite colours — endings with a strong drawing tendency even a pawn or two down.

Opposition — When kings face each other with one square between; the player not to move has the advantage.

Outflanking — A king maneuver that sidesteps around the enemy king to gain ground, typically after winning the opposition.

Outside Passed Pawn — A passed pawn far from the main action, acting as a decoy.

P

Passed Pawn — A pawn with no enemy pawns blocking or able to capture it.

Pawn Majority — Having more pawns than the opponent on one wing, often used to create a passed pawn.

Philidor Position — The drawing R+P vs R defense with third rank technique.

Protected Passed Pawn — A passed pawn defended by a friendly pawn, making it harder to block.

R

Reserve Tempo — A held-back pawn move kept in reserve to lose a move on demand and put the opponent in zugzwang. Also called a spare tempo.

Reti Manoeuvre — The king takes a diagonal path to do two jobs at once — catch a pawn while supporting its own pawn promotion. Named after Richard Réti.

Rule of the Square — Visual method to determine if a king can catch a passed pawn.

S

Shouldering — Using your king's body to block the enemy king's path, like a "body check."

Stalemate — Position where a player has no legal moves but is not in check (draw).

T

Tablebase — Database of perfect endgame play for positions with few pieces.

Tarrasch Rule — The guideline that rooks belong behind passed pawns, whether your own or the opponent's.

Tempo — A single move viewed as a unit of time; "gaining a tempo" means making progress while the opponent does not.

Trebuchet — A mutual-zugzwang position where whoever is to move loses. Also called a full-point zugzwang.

Triangulation — Moving the king in a triangle to transfer the move to the opponent.

U

Underpromotion — Promoting a pawn to a knight, bishop, or rook instead of a queen, sometimes needed to avoid stalemate or to deliver mate.

V

Vancura Position — A drawing defense in rook + a-pawn vs rook where the defending rook attacks the pawn from the side and checks from a distance.

W

Wrong-Colored Bishop — A bishop that cannot control the promotion square of a rook pawn.

Wrong Rook Pawn — A rook pawn whose promotion square is the opposite color to the bishop; with the defending king in the corner it draws even a piece down.

Z

Zugzwang — A position where any move worsens the position; the compulsion to move loses.

Zwischenzug — An in-between move, often a check, inserted before the expected recapture or continuation. Can change the evaluation of a line.