Chess Logic Puzzle ♙ Color The Pieces To Make It Legal ♙ Retrograde Analysis ♙ G. Husserl, 1966

#Chess #ChessPuzzles #LogicPuzzles #ChessforCharity #Heart2HeartInternational #RetrogradePuzzles #ProofGames #Puzzles #Logic
In this video, the goal is to figure out what color the pieces are in this position in order to make it legal. It takes a series of deductions, but it is worth it! If you want to see more retrograde puzzles, let me know! Be sure to subscribe for more chess content!
Thank you!

24 Comments

  1. I like that kind of puzzles (honestly it was the first time to see it). I would like to see more of it.But may be you could colour the "unsolved" pieces in another colour like green? It would help to keep the overview.'

  2. Why the bishop Is impossible To be Black?You Can just move the pawn To promote and capture the Queen On the Next move

  3. this is a cool puzzle! keep up the good work 🙂

  4. It was really entertaining and very well explained. Sherlock was on drugs again. 🧐

  5. what if the bishop was already there before and then this position was reached (i e the white king walks over and lands on the square in the position after the bishop is already on the capturable square)

  6. I think it's important to mention that the last move had to have been made by the piece that landed on d8. The king had been held in position for at least two moves since the pawn on c7 is blocked in by the queen. The only other move would have been the pawn on b7, but that obviously hasn't moved.

    Therefore the last move must have been knight e6 to d8. Especially since if the knight was on f7, it would have been checking the king.

    Great little puzzle! I've never seen something like this 👍

  7. Secretly, the pawn and bishop (on a7 and a8 respectively) are black and the chess game is Chess 960, or Fischer Random chess.

  8. What if the black piece that got captured on d8 was the bishop and black's previous move was king from b8 to c8? Actually, that's wrong, since two of white's pawns are giving check, from a7 and c7 and white cannot move both in one move

  9. So… Can I just say the poor black player got absolutely destroyed in this puzzle/game?

  10. It would’ve been easier to understand if all pieces are grey when we dont know the color

  11. my favorite part that the resulting position isn’t even checkmate

  12. i still believe the piece captured on d8 could have been a black bishop, sure it wouldn’t have been able to enter d8 in this configuration, but it’s possible to shuffle the white pieces around to enter this position, so the black bishop is already there since many moves ago

  13. The piece on d8 was indeed a knight, but a bit more reasoning is required to show that it was not a bishop.
    The reason for this is that "could the bishop not have moved to d8 from f6, g5 or h4 before the white rook moved to f6?" is a question that needs to be addressed.
    And the way to show that this could not have been the case is to prove that blacks last move was to move some piece to d8.
    We know that black's last move wasn't a pawn move, since their only pawn is on its starting square.
    Next, consider if black made a king move. They could not have moved from c7 or b7 because we see other pieces in those squares. They could not have moved from d8 since the assumption that the last move was a king move would put another piece on that square. It could not have moved from d7 because then the two kings would have been adjacent, and finally, it could not have moved from b8 because then the king would have been checked by two pawns at once, and there's absolutely no way for such a double check to be possible.
    Consequently, black's last move could not have been a king move, as there is no legal square for it to have moved from. This finally shows that black's last move was indeed to move a piece to d8, and now that this is the case, we know for sure that white's room on f6 was positioned there when that move was made. Only then can we prove that Ne6-d8 was black's last move.

  14. The only way the position can be legal is if a pawn on c7 captured on d8 and promoted to rook, giving double check.

    This means the king on c8 is black, and thus the pawn on b7 must be black. So the bishop on a8 must be a promoted pawn,and either that pawn or the one on a7 captured towards the a file.

    To avoid any other checks that would make the position illegal, all other pieces must be white. Therefore:

    – black: b7, c8
    – white: everything else
    – last move: c×d8=R+

  15. Before watching the solution:

    I think the answer Black pieces: King on c8 and pawn on b7. Everything else is white. Black's turn to play with white's last move being cxd8=R+.

    A little bit of explanation.

    Since there are a lot of potential checks in this position depending on the colors of pieces queen and rook on d8 are checking both kings, rook on f6 and knight on e8 are checking the d6 and pawn on b7 (if white) is attacking king on c8 (if black). So this is my anchor point for the start.

    Based on the fact that a king can't walk into a check – if queen and king on d6 are opposite color that means last move was queen moving to that square to make a check. But then the rook on d8 would be already checking one of the kings so such a move will be illegal. In a similar way we can conclude about the rook on d8 and king on d6 can't be opposite color. Similar logic about the rook on f8. If they are opposite colors and the rook moved last, then his king was already in check on last move. So the king on d6, queen and 2 rooks must be the same color. But which one? Here the board can gives us a clue considering there are pawns still in play.

    The only possible way that we get into that position in a single move (talking about the checks) is a capture and promotion on d8. Otherwise the king on d6 would have already be in checks while the opponent moves. So it was a discovered check by the queen and a promotion to rook check. And because white's pawn move ranks 2-8 and blacks 7-1 that means that the rook on d8 is white and thus the queen, the other rook and the king on d6. So king on c8 is black.

    If the pawn on b7 is white then that's another check on the already concluded black king which is impossible. So this pawn is black.

    The the bishop on a8 can't be black because there is no way for a black bishop to get there if the pawn on b7 is black and not moved. So bishop is an underpromoted white bishop. The pawn on a7 should be white otherwise there is no way the just mentioned promotion to happen. So it has to be a pawn that has done one or more captures to the towards the a-file.

    That leaves us with the knight. If the knight is black then he is checking the white's king and then last move from white can't be cxd8=R+. So knight should be white.

    So like I stated in the beginning all but king on c8 and pawn on b7 are black. The rest is white and after cxd8=R+ as last move white the move before that was black moving a knight (can't be any other piece cuz otherwise in order to move to d8 it would have checked white's king beforehand) from e6 to d8 just to get captured.

    Edit: Yikes. I can't believe I guessed it right 😀
    Retrogrades are awesome indeed.

  16. What if the board is backwards and the black king is actually all the way up the board? Then the bishop could be black, because it got there and then a black pawn marched forward

  17. Only one king can be under attack, so d8 and c6 are the same colour. And one of those must have just moved revealing the other one's attack. But if it was Qd7c6 then the opposite colour king was already under attack. So the final move was cxd8=R+ with double check on the c8 king.

    That means we must have d8, c6, d6 white, and c8 black, and the white king can't be under attack so e8, f6 are also white.

    Next, the pawn on b7 can't be white because if it were the black king was under attack before the pawn capture. So b7 is black and hasn't moved the entire game. That means that the a8 bishop can only have reached that square via a pawn promotion, so a8 is white, and a7 must also be white because if it were black a promotion on a8 would be impossible.

    So, b7 and c8 are black. Everything else is white.

  18. you should put colour of pieces either grey or half white and black for puzzle.
    is there any possibility also, ie more than one answer

Leave a Reply

Your email address will not be published. Required fields are marked *