story - Copycat Chess (Part 2/3)

The mandarin stared bewildered on the chess board after Li Chai finished his winning move:

1. d4 d5 2. Qd3 Qd6 3. Qf5 Qf4 4. Qxc8#

But it didn't last for long. He grabbed his queen and repeated Li Chais last move while announcing:

What kind of mate is that, if I can mate you as well?

This was of course against the rules, but Li Chai stayed calm and started the second game.

How did Li Chai win the second game?

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The rules (same as in part 1):

• standard chess rules apply, if not stated otherwise


• you play white and your opponent copies all your moves (e.g 1. e4 would be followed by 1. ... e5)


• you are allowed to make "stupid" moves, your opponent will copy all moves regardless how bad they are


• you are not allowed to make moves which cannot be copied, of course except for the last move winning the game

New rule:

• make it impossible for the mandarin to repeat the mating move

The limit for this part is 7 moves.

Answer

This is new for me and I'm not sure but this seems to work:

1. d4 d5 2. e4 e5 3. d:e5 d:e4 4. Bg5 Bg4 5. Q:d8#