Pins: the trap that holds a piece still

Once your child has met the fork, there is another trick waiting for them. It is called a pin, and it is all about trapping a piece so that it cannot run away, even though it is not captured yet.

A pin happens when a piece is attacked, and moving it would leave a more important piece behind it open to capture. The piece in front is "pinned" in place, a bit like a butterfly pinned to a board.

Which pieces can pin?

Only pieces that move in long straight lines can pin: the bishop, the rook and the queen. A pin always happens along a line or a diagonal, with three pieces in a row: the attacker, the pinned piece in the middle, and the bigger piece hiding behind it.

Knights, pawns and kings cannot pin, because they do not attack along a line.

Two kinds of pin

• Pinned to the king. If the piece behind is the king, the pinned piece is not allowed to move off that line at all, because a player may never leave their own king in check. It is completely stuck, unless it can move along the same line, for example by capturing the attacker.
• Pinned to something valuable. If the piece behind is a queen or a rook, the pinned piece is allowed to move. But if it does, the bigger piece behind gets captured. It is legal, just usually a bad idea.

A simple way to say it to your child: "The piece in front is a shield. If the shield walks away, the treasure behind it is in danger."

Why pins are so useful

A pinned piece is often a sitting target. Because it cannot safely move, your child can attack it again, for example by pushing a pawn towards it. The opponent cannot escape by moving the pinned piece, so they may simply lose it.

A pinned piece is also a poor defender. If it is pinned to its own king, it cannot leave the line to capture anything or protect another square, and children can learn to take advantage of that.

Line-up game: put a bishop, rook or queen on one side, then place a "treasure" piece, and one smaller piece in between on the same line. Ask your child, "If the middle piece moves, what happens?" Then swap and let them build a pin for you to spot.

How to practise

Pins suit children who already move all the pieces confidently and have tried forks, often around six to eight years old. Younger children can still enjoy the line-up game above as a looking exercise.

• Look for three in a row. Teach your child to scan lines and diagonals for enemy pieces standing one behind the other.
• Check your own pieces too. Before moving a piece, ask, "Is anything hiding behind it?" This stops them walking into pins themselves.
• Keep it short. A couple of pin puzzles a day is plenty at this age.

In ChessMons, Practice has 20 puzzles for each piece and skill, and coach Tock gives step-by-step hints when your child gets stuck, so they can discover the pin for themselves rather than being shown it.

Once your child can spot a pin, they start to see the board as lines and connections, not just single pieces. That is a big step towards thinking like a chess player.