# Christmas Conundrum

Here is a take on the Christmas challenge for you, Retrograde Chess. Your aim is to identify the missing piece. This position was reached only through legal chess moves.

A word of caution, its tough, it took me a few days to crack and I found coming back to it a regular intervals helped. If you decide to try it, good luck!

Merry Christmas

##### Robin Barnwell

Financial Services

1. joecoolfiftyfive

Without posting all my logic, I can narrow it down to 2 black pieces or 4 white pieces. Are we supposed to be told if the unknown piece is a white or black piece?

2. Robin Barnwell

Sounds like you are making progress. There are no more clues I’m afraid., you need to work-out if black or white.

Hope you don’t give-up; it took me a few days and trying lots of different approaches and blind-alleys to solve it. As I said this is a tough one but there is a solution.

Regards
Robin

3. Scott Seaton

You state that "This position was reached only through legal chess moves". I do not see how this is possible. If you notice, Black is in check, therefore it is Black’s move. With this being the case, White must have just moved to put Black in this position. Due to the position of White’s Rooks, there was no legal way this could have happened.

Please show me the error in my logic. What would have or could have been the last possible legal move?

4. Robin Barnwell

Black is in check and White is in check, how can this be?

Maybe the white King has moved all the way up the board to the eighth rank and is actually behind the black Pawn and not in check at all?

Maybe the Rook on the eighth rank was actually a white Pawn and took a black piece and converted into the Rook? This pawn move caused the black King into check.

There is a lot more to this puzzler!

5. Ahmed

it is a ” blank blank ” (answered correctly, but removed so others can try)

6. Robin Barnwell

Ahmed

Well done! This is no easy puzzle and takes a lot of thought.

Would you like to share your solution or give others the chance to think it through?

Regards
robin

7. p.taylor

It must be a white bishop