Attack and Mate by Sacrifice

ATTACK AND MATE BY SACRIFICE Zheng Defeng's 1966 Xiangqi manual of sacrificial attack: 81 middlegame positions in which one side hands over material on purpose and mates. Every refutation attached, annotated in three languages, with an NNUE engine. Offline. Around 1570 a Ming collection of chess positions was printed with a short essay on play at the back, and halfway down it stands the clause this app exists to teach: give a piece away and you must come away with the move. Material is not the currency of this game. Time is. That is why a sacrifice can be the strongest move on the board, and why most are bad. THE BOOK Methods of Attack and Mate by Sacrifice, compiled by Zheng Defeng, People's Sports Publishing House, 1966. Seventy five pages, and a reputation out of all proportion: a 2011 Chinese survey put it first in its generation. Its contents list eighty numbered studies in seven classes, grouped by the force that delivers the finish, and these are middlegames, not endgames: 22.6 pieces on the board on average, seven to thirty one. That is this app, class for class and number for number, plus one supplementary position, 46A, for eighty one in all. SEVEN CLASSES Three pieces on one flank, runs the proverb, and the game is decided: strength is a combination, not a quantity. Chariot and Pawn, 6. The thinnest pair there is, so the Pawn must become a mating piece. Chariot and Horse, 5. On one key square the Horse gives no check: it covers the palace centre so a Chariot can land there, take the defended Advisor and mate a General still holding both. Chariot and Cannon, 11. The Cannon kills only over something, and that something is often the defender's own Advisor. Six give a Chariot away. Chariot, Horse and Pawn, 4. The Pawn supplies the square a Chariot and Horse cannot. Chariot, Cannon and Pawn, 9. The cheapest way to mate a full defence, and holds the book's most analysed position, forking eighteen ways. Chariot, Horse and Cannon, 37. The heart of the book, and the best ground for sacrifice: give the Chariot away and two mating pieces remain. Sixteen do. Chariot, Horse, Cannon and Pawn, 9. The full battery, densest branching. THE ARITHMETIC In the main lines alone the attacking side allows 33 Chariots, 16 Cannons, 14 Horses and 18 Pawns to be taken without recapturing. Thirty two studies give away a whole Chariot; two give up both. And before anything is sacrificed the attacker is already a piece down in twenty positions, level in fifty eight, ahead in three. THE OBJECTION Sacrifice puzzles have a bad habit: mate follows in five and you learn nothing. Does the book say what happens when the defence declines? The main lines come to 1,404 half moves, the variations to 1,669 across 217 branches, so there is more analysis off the main road than on it. Nor are the verdicts uniform: one study ends in a draw, one with Black winning, and one note says Red is up but has no forced win. INSIDE, AND HOW TO STUDY IT 81 studies, 3,073 half moves, every variation verified legal. 306 annotated points, each in Chinese with English and Vietnamese alongside. Replay. Step through any study a move at a time and walk into any branch. Learn. A board where nothing moves by itself: you take both sides by hand and find the move yourself, with arrows you can switch off. Go off book. Play the move the compiler never wrote down, then jump back to where you left it. Ask the engine. A full strength NNUE neural network engine on your device, nothing sent anywhere. Your own board. Three languages, 13 sizes, 35 replay themes, 6 study themes, 5 colours, 5 fonts, light or dark. Offline. No account, no ads, no tracking, no permissions.