[Retros] rstan

[Francois Labelle]

On 10/05/2013 09:18 PM, Noam Elkies wrote:


> How about:

>

> A = ... e6

> B = ... Qg5+ ... Qb5+ ... Qe5+

> C = ... Bc5 ... Kf8 ...#


This works for n >= 1:
1. d4 e6
2. Kd2 Qg5+ 3. Kd3 Qb5+ 4. Ke4 Qe5+
5. dxe5 Bc5 6. Qxd7+ Kf8 7. Qd8#

but it is cooked for n = 0:
1. c3 e6 2. Qa4 Bc5 3. Qh4 Kf8 4. Qxd8#
1. c3 e6 2. Qa4 Bc5 3. Qxd7+ Kf8 4. Qxd8#
1. c4 e6 2. Qa4 Bc5 3. Qxd7+ Kf8 4. Qxd8#
1. d3 e6 2. Qd2 Bc5 3. Qg5 Kf8 4. Qxd8#
1. d4 e6 2. Qd2 Bc5 3. Qg5 Kf8 4. Qxd8#
rnbQ1knr/pppp1ppp/4p3/2b5/4P3/8/PPPP1PPP/RNB1KBNR (5 solutions)
rnbQ1knr/pppp1ppp/4p3/2b5/8/4P3/PPPP1PPP/RNB1KBNR (5 solutions)
(for a total of 15 solutions)

So it works if you glue one copy of B to A. The shortest line is 6.5 moves.

You were trying to use different end-positions for n = 0 and n >= 1? I 
guess I didn't disallow that. Sneaky! :)

     François