# Chess with symmetric move-square

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?

• Hi @ArtemLugin, welcome to Puzzling SE! (Take the tour if you haven't already!) Can you clarify if the same piece has to occupy black's move-square as white's, or can any piece count? For example, would something like 1. e4 e5 2. Be2 Ne2 be acceptable? Or is only Be7 by black possible?
– HTM
Commented Apr 8, 2019 at 0:59
• @PiIsNot3 Its doesn't have to be the same piece. Only the corresponding symmetric square. Assuming you mean Ne7 not Ne2 yes, thats acceptable Commented Apr 8, 2019 at 1:08
• @RewanDemontay the game ends at the capture, theres no need for the capture to occur twice. If it ends with a white move, a valid move by black must be shown to exist (in description) Commented Apr 8, 2019 at 1:10
• I can't accept your edit as it contains improper grammar and is inaccurate. I'm open to suggestions and edits to improve understandability Commented Apr 8, 2019 at 1:19
• I think the question is clear enough, perhaps some terminology can be fixed but at least I can tell what’s being asked
– HTM
Commented Apr 8, 2019 at 1:32

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

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

• You're on the right track. There are several ways to get it in 5 moves with white capturing the piece Commented Apr 8, 2019 at 2:30
• The question you linked was the inspiration. Thought I'd spice it up. a-Rook takes h-rook looks very interesting as well Commented Apr 8, 2019 at 2:36
• Great job! Marked as correct Commented Apr 8, 2019 at 2:51
• @ArtemLugin While you're free to Accept whichever answer you think best addresses the puzzle, it's a bit unclear why you would select one that only answers one of the three parts of your question. Did you mean to pick this one?
– Rubio
Commented Apr 8, 2019 at 5:22
• @Rubio of the 2 answers, neither solves all 3 questions correctly. This answer contains the correct solution to the most difficult of the 3, while the other the latter 2. If that answer is updated I'll consider marking it correct. Commented Apr 8, 2019 at 6:08

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:

Knight X Rook:

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

Proof Game:

Queen X Bishop:

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

Proof Game:

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:

• Oooh, I found one I really like. Looks kind of flashy IMO: 1.e4 e5 2. Qe2 Be7 3. Qb5 Bb4 4. Qxb4 Commented Apr 8, 2019 at 2:03
• Great solutions. RookxRook can be improved Commented Apr 8, 2019 at 2:11
• Should I add another or 2? Commented Apr 8, 2019 at 2:13
• @ArtemLugin generally, if you're going to change the question (by adding questions) simply ask a new question! Commented Apr 8, 2019 at 2:14
• The shortest is 5 white moves Commented Apr 8, 2019 at 2:28