Is there a position with the stupidest possible move?

Question

I define a stupid move as a move that

1. puts the opponent in zugzwang so that all their moves result in mate in one (weaker version: a loss);
2. is chosen instead of a move that gives mate in one (weaker version: a limited number of moves).

A move is more stupid as the ratio of type 2 moves over type 1 moves grows. I'm looking for a position with the most stupid move possible.

This question is similar to these interesting questions:

• Position with the most (or many) distinct refutations?
• Is there a double-forced mate position?

Answer 1

Every single legal move from White checkmates—except the extremely stupid Bd7. There are 12 (discovered) checkmates with the rook on g2 alone. After the stupid move, Black is forced to give checkmate in 1.

EDIT: Thanks to @Noam D. Elkies for his improvements: Here Black has the choice between no less than 6 legal moves - all of which checkmate!

        [FEN "k1B5/p1P1p3/P3P3/8/1p6/bpp5/qnp3R1/2K4B w - - 0 1"]

Interesting side note: We are in effect asked to create a chess puzzle for a chess variant where the goal is not to give checkmate, but to get checkmated, with only one losing move. This chess variant can be played against the WorstFish lichess bot. It's actually quite hard to make it win against you.

Answer 2

On 4 January 2007, in item 334 of his Open Chess Diary, Tim Krabbé considered the question of what is the worst chess move. His specification was "White has n moves, (n-1) of which would mate Black in 1; the nth forcing Black to mate [them] in 1." The higher n, the better. Noam Elkies found an example with n=28.

[Title "Noam Elkies, after H H Cross"]
[StartFlipped "0"]
[fen "8/1b1nn3/p1N2p2/P1r5/P3KPr2/QBk1NRP1/P2R1P2/4B3 w - - 0 1"]

1. Qxc5+ Nxc5#

Krabbé goes on to list other examples with higher n, but they entail the use of promoted pieces in the diagram and/or promotion moves. One example:

[Title "Joaquim Crusats and Kasper Henriksen (after Dittmann), 2007"]
[StartFlipped "0"]
[fen "b2qQRQ1/3P1N1Q/n2K1k2/3P3Q/4P1Qp/5pNP/1R5b/B7 w - - 0 1"]

1. Qe7+ Qxe7#

Answer 3

Here's an idea, which I'm sure of can be optimized:

[FEN "Q2Q1B2/4R3/N1Q5/3Q4/2Q2Q2/k4NQ1/p1Q5/K1b1Q3 w - - 0 1"]

1. Qb2 forces Bxb2#; there are more than forty mate-in-ones you can choose from instead.

Answer 4

Position with just knights, where one white move mates in one and another move forces black to mate in one. Not many stupid moves, but also not many pieces (and piece types).

[Title ""]
[Fen "8/8/8/5N2/4N1n1/7k/4n3/7K w - - 0 1"]