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# What is the position with the most possible checkmates in 1?

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What is the highest possible amount of checkmates in 1 that can be legally obtained? The best i could come up with is 22.

i counter 65

73 since 9 queens is legal

we have enough material for this but obtaining this position i think would be impossible. since you can stalemate

For a legal position with promoted pieces allowed, the record is apparently 105 mate-in-1 moves.

Note the OP position is indeed legal: Black's last move was to move the K from g8 to h8, and before that White's move was a double-check, gxf7+.

The second position is a good effort with multiple queens, but it's illegal because no matter where the black king just came from, it would be in an impossible check from various pieces. The position can be made legal by, e.g. adding a black pawn on a2, which doesn't seem to affect the mates.

TiltedDonkey wrote:
Chess_Player_lol wrote:

73 since 9 queens is legal

not legal - what would black's last move have been

A piece movement (from say a surviving knight), followed by a capture of that knight by a White queen.

eric0022 wrote:
TiltedDonkey wrote:
Chess_Player_lol wrote:

73 since 9 queens is legal

not legal - what would black's last move have been

A piece movement (from say a surviving knight), followed by a capture of that knight by a White queen.

That doesn't work because such a sequence would mean Black is to move in the diagram. With Black to move, there isn't any mate-in-1 at all, so the position would be pointless.

This is legal as White could have promoted 3 times to queen and Black could be aimlessly toggling the Knight:

All of these moves are mate:

13 Queen moves: Qxa8, Qb8, Qad4, Qc3, Qed4, Qed5, Qdd4, Qde5, Qdf6, Qge5, Qgf6, Qg7, Qg8

12 Pawn moves: bxa8=Q, bxa8=R, b8=Q, b8=R, c8=Q, c8=R, d8=Q, d8=R, e8=Q, e8=R, f8=Q, f8=R

12 Rook moves: Ra2, Rc2, Rd2, Re2, Rf2, Rg2, Rh2, Rb6, Rb5, Rb4, Rb3, Rb1

2 Knight moves:  Nfg6 or Nhg6

1 King move:  Kg6

That's 40 mate in 1's based on a legit (albeit stupid) position.

Rocky64 wrote:
eric0022 wrote:
TiltedDonkey wrote:
Chess_Player_lol wrote:

73 since 9 queens is legal

not legal - what would black's last move have been

A piece movement (from say a surviving knight), followed by a capture of that knight by a White queen.

That doesn't work because such a sequence would mean Black is to move in the diagram. With Black to move, there isn't any mate-in-1 at all, so the position would be pointless.

Right, I focused so much on the position that I forgot this was White to move.

All the surrounding squares of the Black king are each attacked by at least two queens, so Black only has one pawn move - from a7 since White has a complete set of pieces. Seems like there might not be sufficient moves for Black to get the king to that position.

CraigIreland wrote:

Regarding the 105 mates in 1 position from the composition referenced in comment #5 and posted in comment #6 my friend John Bonnett was interested if the position could be obtained legally and the minimum amount of moves it would take.  Here is his legal effort with the minimum 62 moves required to reach the position:

composition position

What is going here?

SWAP2009 wrote:

What is going here?

Great question!

And to think of it, all the moves were legal in Mr. Bonnett`s solution!

Chessflyfisher wrote:

And to think of it, all the moves were legal in Mr. Bonnett`s solution!

Yes, whether the position could be obtained legally was the main thing he wanted to see.

Hmmm interesting. What then is the position with the most possible checkmates in 1 in which you can make the wrong move and then lose on time?

what about one with the highest possible number of stalemates?

Hidethe_painHarold wrote:

what about one with the highest possible number of stalemates?

This one has 85 stalemating moves (legal position with promoted pieces allowed), where Black is not already in stalemate initially. Not sure if it's the current record.

1 Year later, this conversation is still being watched for gaining information by young, fresh chess scholars wannabe

And young overviewers.