Pin

A pin is a rook, bishop, or queen aimed at a piece through exactly one piece of the target's color. The piece under the line is undefended, or worth more than the attacker. A pin to the king always counts.

Why you should notice it

The piece in the middle cannot step aside without exposing what stands behind it. If you only look for attacks that land immediately, you miss the piece that is stuck on that line.

When to check it

During threat assessment, ask which of their rooks, bishops, and queens pin your pieces. While finding the best move, ask which of yours pin theirs. The piece in the middle matches the target. A discovered attack, where that piece matches the attacker, is a different line.

Why players miss it during games

The pinner is not touching the piece it pins, so the line looks quiet. Players also mix a pin with a discovered attack, because both have one piece in the middle. The color of that piece is the whole distinction.

How WayChess trains it

You draw an arrow from the pinner to each piece behind a pin, first on your pieces, then on the opponent's. Feedback shows missed lines in amber and extra arrows in red. If none qualify, you submit with no arrows. Pin or discovered attack names one useful x-ray that is already drawn.

Related checks

Useful x-ray is the wider filter: the line matters, whether it is a pin or a discovery. Discovered attack is the other kind, where the piece in the middle matches the attacker and can leave the line. Pinned defender marks a piece whose protector is pinned.

See all habits.