In chess, the white player makes the first move.
It is generally understood that this gives white a minor advantage, with a win rate of 52-56%.
In this initial position, white actually has checkmate in one move!
However, the player who makes the first move doesn't necessarily have the advantage...
Can you find an initial position where black's pieces still mirror white's, but black always wins?
Challenge
Rearrange all the pieces on a standard chessboard, maintaining symmetry, such that black can force checkmate.
Conditions:
- Black's pieces still mirror white's pieces.
- No pieces on the opponent's half.
- No pawns on the first rank (row).
- All standard pieces must be on the board. No more, no less!
- White to play first, but black has checkmate in x moves.
Extra!
Bass has posted the first solution! It's not the solution I found and uses a slightly different approach. So, to make it more unique I would like to add a further challenge:
- Find the position resulting in the fastest possible forced mate.
Notes and hints:
- The bishops can be on the same colour squares.
- I've found the board editor on lichess.org very useful for finding a solution:
- The position shown at the top of this puzzle is here.
- Use the "Analysis Board" with stockfish turned on to check your solution. If it shows you #-1, #-2 etc. then you've forced a black checkmate!
- There may not be one unique solution. I was unable to find any other solutions in several hours, but I found the premise interesting, and the puzzle was challenging.
- I hope it's fun to solve! I've not been able to find information about a puzzle like this online, so it's possible I've missed something obvious. These hints are based on how I worked out my solution, but let me know if there's something wrong!
- Hint 1:
Try to restrict the moves that white can make! If white has a choice, they will choose the move that doesn't lead to checkmate.
- Hint 2:
Try to block almost every piece in, especially the king. Test out various scenarios without worrying about piece restrictions, and check your strategy works!
- Hint 3:
White and black initially have the same moves available to them. If black could deliver checkmate, white could do so first! So, white must be forced to make a move which opens up additional possibilities for black.
- Hint 4:
The only 3 ways black can get additional movement options are if:
1) A black piece becomes unpinned
2) White puts a piece in front of an attacking pawn
3) White captures a black piece that was blocking something. - Hint 5:
Forcing white to sacrifice a piece to a black pawn is important - it allows black to make a capture move that was not available to white. Use this pawn movement to your advantage!