Atomic Xiangqi: twelve engine games

The variant lab’s engine games under the rules Mistboard plays: ten wins by the stronger engine (ten million nodes against one million, six by explosion and four by checkmate) and the two best-play draws that show what the game looks like when nobody errs. Notes mark every explosion and the move that decided each game. Rules: mistboard.com/rules/atomic-xiangqi

12 chapters

1. Win 1: explosion after a seventy-move hunt (Red)145 moves

   Red (10 million nodes) against Black (1 million). The longest win on file. Level for six moves, then Black’s cannon swap at 3…Cf6 hands Red a pawn, and by move 15 Red is winning. What follows is the hunt: twenty-two moves in this game are check in the wide sense, the black genera…

   Cf6: the cannon pairing Red wanted. Red +1.8 already.

2. Win 2: checkmate after the palace is emptied (Black)96 moves

   Black (10 million nodes) against Red (1 million). Red holds until 25.Cd5; then 28…Rxc5 takes a chariot and a cannon with one capture, 37.Rxf2 costs Red its own advisor to the blast, and from move 43 Red is lost. The finish is the unusual part: Black blows up both of its own advis…

   Cd5: Red’s cannon steps into the open file. Black is better from here (-2.2).

3. Win 3: a horse blasts its own advisor, and the file opens (Red)75 moves

   Red (10 million nodes) against Black (1 million). Level until 18…Cd2 leaves the back ranks; then 21…Hxf9 takes a cannon and blows up Black’s own advisor on f10 with it, and the palace never recovers. Red wins by explosion on move 38, the chariot taking the cannon on d8 beside the…

   Rf8: already a pawn and a half for Red.

4. Win 4: three pieces in one blast (Black)68 moves

   Black (10 million nodes) against Red (1 million). Red’s 7.Cxh10 wins a chariot for a cannon and Red is lost eight moves later anyway: 11.Pc5 walks into a corner collapse, and 18…Hxb1 takes the horse with the chariot on a1 and the elephant on c1 beside it. The general is chased to…

   Cxh10: cannon for chariot. The shot takes only the chariot, and on paper Red is a little better.

5. Win 5: the soldier takes the horse, the blast takes the advisor (Red)75 moves

   Red (10 million nodes) against Black (1 million). 9.Cxf8 wins a chariot for a cannon; 22.Pxf9 takes a horse with a soldier and the blast removes the advisor on e9 beside it, which is the move that opens the palace. Black’s checks on moves 28 and 29 change nothing, and the horse f…

   Cxf8: cannon for chariot, the shot taking only its target.

6. Win 6: a red horse walks into the middle (Black)62 moves

   Black (10 million nodes) against Red (1 million). 16.Hg3 is the losing move (-10.7), 20.He4 and 21.Hxd6 make it worse, and Black lets one mate slip (22…Rh7) before finding the finish: 31…Rxe2+ takes the advisor beside the general on e1.

   Hg3: the horse leaves the flank and Black’s attack has a target. -10.7.

7. Win 7: two self-blasts, one each (Black)64 moves

   Black (10 million nodes) against Red (1 million). Both sides blow up their own pieces: 10…Hxf9 costs Black an advisor, 19.Hxb1 costs Red an elephant, and the second matters more (-11.8). 23…Hxe2 takes the advisor and clears the elephant and the horse beside it, and the mate comes…

   Hxf9: the horse takes the cannon, and Black’s own advisor on f10 goes with it.

8. Win 8: the shortest win, twenty-three moves (Black)46 moves

   Black (10 million nodes) against Red (1 million). 6.Kd1 steps the general into the corner of the palace early (-2.0), 8…Hxh1 takes a horse and a cannon with one capture, and 18.Ce4 is the losing move. 23…Rxf1+ takes the advisor beside the general on e1.

   Kd1: the general leaves e1. -2.0, and it never gets back.

9. Win 9: a soldier takes three pieces (Red)69 moves

   Red (10 million nodes) against Black (1 million). 12…Pg6 is the mistake (+5.2), and 15.Pxc9 is the game: a soldier takes the chariot on c9 and the blast removes the elephant on c10 and the horse on c8 as well. Red converts by explosion on move 35.

   Pg6: +5.2 for Red.

10. Win 10: mated by a soldier (Black)60 moves

    Black (10 million nodes) against Red (1 million). One explosion decides it: 24…Rxd3 takes the advisor on d3 and removes the elephant on e3 and the cannon on d2 with it, and Red’s palace is bare. The mate is a soldier’s: 30…Pe1+.

    Pe5: -8.8.

11. The cork: a cannon in front of a chariot (2 million a side, draw)34 moves

    Both sides at two million nodes. After the exchanges the ending is the new chariot-against-cannon idea. Black’s general is on f10 and Red’s chariot wants the f-file; Black’s cannon stands directly in front of the chariot and slides sideways with it. It blocks the chariot and, bec…

    Pxc5: soldier takes soldier. A soldier is removed only by capture.

12. Best play at twenty million nodes (draw)88 moves

    Twenty million nodes a move for both sides, the deepest game on file. 2.Pc5 is the only swing (-0.3), then a game of trades: 7…Rxb9, 9.Rxb10 taking the elephant beside the chariot, the cannon shots 15.Cxh4 and 16.Cxf7, five soldier captures, and a level ending that repeats after…

    Rxb10: the chariot takes the chariot, and the elephant on c10 goes in the blast.