📚 Lanke Shenji — a Ming-dynasty endgame manual
Red to move and mate in 4 — with every single Red move a check, so Black never gets one breath. The forces say it should be impossible: Red has one Rook and two Knights, while Black has two Rooks, a Cannon and two Pawns, far the heavier army. But Black's general is already pinned high by Red's rook, and the two knights close in like hands reaching for something on the seabed. Hải Để Lao Nguyệt — 'scooping the moon from the bottom of the sea' — is an idiom for a hopeless task, yet this variant from Lạn Kha Thần Cơ is anything but hopeless: four moves, four checks, mate. This is also the position our daily Facebook clip animated. The story behind the name is in this page's Anecdotes section. Can you find four consecutive checks that end in mate?
✓ Engine-verified — The Fairy-Stockfish engine (NNUE) confirms Red checkmates in 4 moves — the main line was checked move by move, every move legal. Date checked: 2026-11-02.
Scooping the Moon from the Seabed: A 'Hopeless' Task That Ends in Mate in Four
Four moves. All four are checks — the opponent does not get a single breath. That is how Hai De Lao Nguyet (Scooping the Moon from the Bottom of the Sea) ends: Red moves first and mates the Black general at the very bottom of the board. Yet its name is an idiom for a hopeless task. Hopeless — and…
The Rotted Axe Handle: The Lanke Legend Behind This Position's Book
A woodcutter climbs a mountain, stops to watch two old men play a board game, and when the game ends, the handle of his axe has rotted away — and a hundred years have passed in the world below. This is the legend of Lanke, "the rotted axe handle", and the book containing the Hai De Lao Nguyet…
Stories around this position — storytelling, not part of the engine-verified content.
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