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TacticsPlay as white

Kill Box Mate

A rook checks along the edge while the queen, two squares from the king, seals the squares in front of it — together they draw a box the king cannot leave.

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Introduction

The kill box is a rook-and-queen mate on the edge of the board. The rook gives check along the edge; the queen, standing two squares away from the king, covers the squares in front of it. Between them they draw a three-by-three box the king cannot step out of. The king's own pieces often fill the last gap.

Lesson Content

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Black's king on e8 is hemmed in by its own queen on d8 and rook on f8, and White has a queen and a rook aiming at it. Qxe6+ takes a pawn with check on the e-file; Black's only defence is to block with the queen, Qe7 — and that queen is now pinned against the king. Then Rc8 is checkmate: the rook checks along the back rank, the queen on e6 covers d7 and f7, and the pinned queen cannot step in the way.

Mating NetPin
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1. ..Qxe6+

Qxe6+ checks the king along the e-file. Black has one legal reply, the block 1. ..Qe7 — and the blocking queen is pinned to the king. Now Rc8 is checkmate: the rook covers the back rank, the queen on e6 covers d7 and f7, and Black's pinned queen cannot move to d8 to block.

Mating NetPin
Alternative Moves
Qxb7 — Qxb7 grabs a pawn and lets the king off the hook: 1...Qxd4+ takes a pawn back with check, and Black's queen and rook start hunting the white king — the mate is gone and White is the one in danger.
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2. Rc8#

Checkmate — the kill box. The rook on c8 checks along the back rank and covers d8; the queen on e6, two squares in front of the king, covers d7 and f7 and pins the queen on e7 so it cannot block; f8 is Black's own rook. Three squares wide, three squares deep, and the king is inside.

Mating NetPin
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The same box in a corner. White's queen on c6 already covers b7 and the corner square a8. Rd8+ checks along the back rank and leaves the king one square, a7 — c8 and a8 belong to the rook, b7 to the queen. Then Ra8 is checkmate: the rook on a8 is protected by the queen, the queen covers b7, b8 is on the rook's rank, and b6 is Black's own pawn.

Mating NetKing Attack
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3. Rd8+

Rd8+ checks along the back rank. The king has one square, a7 — and there Ra8 is checkmate: the rook on a8 is protected by the queen on c6, the queen covers b7, the rook covers b8 and the a-file, and b6 is Black's own pawn. The queen mating on a8 works just as well.

Mating NetKing Attack
Alternative Moves
Qxc7+ — Qxc7+ is check, but the c7-pawn is protected by the king: 1...Kxc7 takes the queen, and White, a queen down, is lost.
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Black's queen on f2 and pawn on f3 are next to White's king, so White must mate at once. The queen on e6 covers e7, f7 and g8; the black king on f8 has its own bishop on h8 beside it. Which move is checkmate?

Mating NetKing Attack
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In a kill box mate, what does the queen do?

Mating Net

Key Takeaways

  • The rook checks along the edge; the queen closes the box — not the other way round.
  • A defender that blocks the first check is often pinned, so it cannot block the second.
  • Count the three-by-three box: every square the king could step to must be covered or occupied by its own piece.

Now play it through

Step through every move on a real board, try the wrong ones, and ask Knighty why they fail.

Practice Interactively

Related Lessons

Hook Mate

Sacrifice and King Attack

Anastasia's Mate

Summary

Kill box mate: rook check along the edge, queen two squares from the king sealing the squares in front of it, and the king's own pieces filling the gaps. Look for it whenever queen and rook attack a king on the back rank or the edge file.

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Next in this course

Vukovic Mate

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