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Seeing the meteoric rise in popularity of Duck Chess (full rules), I'd like to ask how to stalemate the fastest (from the starting position) in this variant, because the stalemated player wins here.

Duck chess rules (basic): The duck is a brick; you can't move through or onto it. Knights can jump over the duck. Each move, first move a normal piece, then move the duck to an empty square. There is no concept of "check". Capture the opponent's King to win. Stalemated player wins.

Note that because there is no check, it's much harder to find a stalemate than in normal chess.

For example, black is stalemated in the following position (black pawns go up): enter image description here

You can paste the following Fen4 into the chess.com analysis board to recreate the position.

Y-0,1,0,1-1,1,1,1-1,1,1,1-0,0,0,0-0-{'pawnBaseRank':5,'wb':true,'dim':'8x8'}-
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,1,rK,6,x,x,x/
x,x,x,5,yP,yP,yP,x,x,x/
x,x,x,5,Θ,yB,yK,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x

You can also start a game or find a game to get a feel for the rules.

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  • 1
    FWIW there's a similar but even more economical stalemate with only K/KPP and the duck: White Kf2, Black Kh1 Pg2 Ph2, Duck g1. Commented Oct 11, 2022 at 2:38
  • Yes @NoamD.Elkies yours is probably with the fewest pieces (K/KPPD) and unique up to symmetry (putting it in a different corner or with different colours). Commented Oct 11, 2022 at 11:02

2 Answers 2

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I bid 10.5 moves. On the last move, the duck lands on g6 to complete the stalemate.

[FEN ""]

1. e4 d5 2. Qe2 a6 3. Qxa6 h5 4. Qxb7 Ra6 5. Qxb8 Rah6 6. h4 f6 7. Qxc7 Kf7 8. Qxd8 Kg6 9. Qxd5 Bf5 10. exf5+ Kh7 11. Qe6
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  • 2
    Oooh nice steady improvements! Now very close to the 9.5 move record for normal chess. Commented Oct 9, 2022 at 1:55
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    Looks good, and I think this is as good as one can get
    – Laska
    Commented Oct 11, 2022 at 14:48
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Welcome to sDuckExchange.com :)

Since there are no checks in Duckland, a typical stalemate is usually a loss of the stalemated player! Since there are no checks we need the king to be smothered, and for smothering units themselves to be blocked, not pinned. That is necessary & sufficient.

I have a solution in 31.0 moves in which additionally no units have been captured, and the duck might be located on any empty square. However the position is truly "fowled", in Duck Chess terminology, so White (to play) has won the game.

Click on "End" in the animation to see the final position. Since the actual duck's location is not important, I don't include it so I can show animation. I have a proof game just for, well, proof, but it's obviously far from unique.

[FEN ""]

1. Nc3 a6 2. Rb1 a5 3. Ne4 a4 4. b3 b6 5. Bb2 b5 6. Qc1 c6 7. Kd1 d6 8. Ba1 e6 9. Qa3 f6 10. Kc1 g6 11. Kb2 h6 12. h3 h5 13. Kc3 g5 14. Kd3 f5 15. Qc1 a3 16. Rb2 e5 17. Qb1 d5 18. Ke3 b4 19. Kf3 c5 20. Kg3 c4 21. Kh2 c3 22. Nf3 d4 23. Kg1 h4 24. Nc5 e4 25. Rh2 e3 26. Kh1 f4 27. Ng1 g4 28. Nd3 g3 29. Nc1 Bb7 30. d3 Ba6 31. f3 Bc8

Surely this can be improved, but it points the way.

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  • 1
    Why does Loyd's 12(?) move stalemate construction not work? The duck should be irrelevant for helpgames. Commented Oct 8, 2022 at 11:57
  • Yes the duck is irrelevant but the lack of checks is not. For duck stalemate, the king must be smothered by blocked not pinned units. So Loyd's 9.5 move stalemate is a loss for Black
    – Laska
    Commented Oct 8, 2022 at 14:05
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    @HaukeReddmann to be fair, the duck can assist in blocking. Commented Oct 8, 2022 at 16:01
  • 1
    @Laska: Oh, I see. I'm an OTB player not accustomed to suicidal kings. :-) So, shortest h= with white erlking. Commented Oct 8, 2022 at 16:30

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