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Every move in chess involves moving a piece to a square. Let us call this square the "move-square" for that turn.

In the following, the move-square of the black player must be symmetrical (over the obvious center-horizontal) to the move-square by white on that turn. The requirements may be met with a white move, but an additional valid move for black must be shown to exist. This extra move is not included when counting the number of moves taken to reach one of the below conditions.

What is the shortest sequence (with symmetrical move-squares) resulting in a Rook x Rook capture?

Resulting in a Knight x Rook capture?

Resulting in Queen x Bishop capture?

Partial (will update as I go)

R x R (3rd attempt)

I got it! 5 moves:

1. a4 a5 2. Ra3 Ra6 3. Rh3 Rh6 4. d3 d6 5. Rxh6 Apronus link

The h3 square is covered by the black bishop.

Note that 5 is the absolute minimum number of moves needed, since it takes at least 3 moves to make the rooks attack each other, and they can’t directly take each other on the 4th move.

R x R (2nd attempt)

I found a 6 move solution:

1. a4 a5 2. Ra3 Ra6 3. Rb3 Rb6 4. c3 Nc6 5. Rb5 Nb4 6. cxb4 Rxb5

Apronus link

R x R (1st attempt)

This question demonstrates a 7 move sequence, but since we don’t have to copy each others’ moves, only the squares, we can also do the more interesting


1. a4 a5 2. Ra3 Ra6 3. Rc3 Nc6 4. e4 Ne5 5. Rc5 Nc4 6. c3 Rc6 7. Bxc4 Rxc5

Apronus link

Under your rules, here are my answers.

Rook X Rook:

1. g4 g5 2. h4 h5 3. gxh5 gxh4 4. h6 h3 5. h7 h2 6. hxg8=R hxg1=R 7. Rgxh8

Proof Game:

Apronus

Knight X Rook:

1. Nf3 Nf6 2. Nh4 Nh5 3. Ng6 Ng3 4. Nxh8

Proof Game:

Apronus

Queen X Bishop:

1. e4 e5 2. d4 d5 3. Bg5 Bg4 4. Qxg4

Proof Game:

Apronus

UPDATE: Do you mean improve my Rook X Rook game like this?

1. a4 a5 2. Ra3 Ra6 3. Rb3 Rb6 4. Rxb6

Proof Game:

https://www.apronus.com/chess/pgnviewer/?m=a4_a5_Ra3_Ra6_Rb3_Rb6_Rxb6