3
$\begingroup$

It’s Black to move. What must Black do in order to help White castle queenside in just 11 moves?

enter image description here

$\endgroup$
  • $\begingroup$ It seems like there are quite a lot of ways to do this. Is there some extra clever thing going on here that no one has spotted yet? $\endgroup$ – Gareth McCaughan Oct 17 at 23:36
  • $\begingroup$ Ah. I forget to specify something. $\endgroup$ – Rewan Demontay Oct 17 at 23:37
  • $\begingroup$ "In just 11 moves" does indeed narrow it down further. $\endgroup$ – Gareth McCaughan Oct 17 at 23:38
  • $\begingroup$ Very much so. I designed this problem during this summer. I recently shelled it out if my personal archives of creations. $\endgroup$ – Rewan Demontay Oct 17 at 23:39
3
$\begingroup$

This seems to work

1. -, Kg1
2. h5, Bg2
3. h6, Bf1
4. h4, Be2
5. h5, Bd1
6. h3, Be3
7. h4, Rc1
8. a5, Rc4
9. a6, Bb3
10. axb3, b2=N
11. bxc4, Nd2
12. O-O-O, -

$\endgroup$
  • $\begingroup$ A neater approach, I think, than mine. Mine was a bit "brute force". Interesting that it's the same length. $\endgroup$ – Dr Xorile Oct 18 at 1:13
  • $\begingroup$ Thanks, but you showed there isn't a unique solution. :) $\endgroup$ – Jens Oct 18 at 1:21
  • $\begingroup$ Now there is a unique solution. $\endgroup$ – Rewan Demontay Oct 18 at 1:35
3
$\begingroup$

Here's an answer. It's 11 moves by black and by white. Same length as @Jens:

1... Kg1 2. e5 Bg2 3. h5 Bxh3 4. h6 Bd7 5. e6 Kg2 6. exd7 Kg1 7. d8=Q Kg2 8. Qd1 Kg1 9. Qxc1 Kg2 10. Qxb1 Kg1 11. Qxb2 Kh1 12. O-O-O#

solution gif

$\endgroup$
  • 1
    $\begingroup$ That seems to be only $11$ moves for white, like my solution? $\endgroup$ – Jens Oct 18 at 1:07
  • 1
    $\begingroup$ Oh, yes. I can't count. LOL. Yes, so the same length as your solution! Although a totally different approach. $\endgroup$ – Dr Xorile Oct 18 at 1:10
2
$\begingroup$

One way is:

1... Kg1
2. d5 Bg2
3. h5 Bf1
4. d6 Be2
5. h6 Bd1
6. h4 Be3
7. h5 Bb6
8. h3 Bc7
9. dxc7 d6
10. c8=Q d5
11. Qa6 d4
12. Qxa3 d3
13. Qxb2 Rxb2
14. a3 Bb3
15. a4 Bg8
16. O-O-O

$\endgroup$
0
$\begingroup$

After

1. ... Kxh2 White has six pawn moves before they have to move their King. Black can then play Bg2-f1-d3-g6 (somewhere in the line, White can play e5) so that White can play hxg6 and promote their pawn.

From there, I believe Black can essentially waste their turns playing Kh1-h2/g1 ad infinitum while White cleans up the left side of the board and eventually plays O-O-O.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.