[Retros] Ortho-reconstructions

[Joost de Heer]

On 03/28/2010 08:29 PM, Pascal Wassong wrote:

> Hello,

>

> I studied this paper, and the previous ones, with great interest.

>

> The proof game of problem 18, by Guus Rol, is not unique.  For example:

>

> 1.c4 e6 2.c5 Bxc5 3.Qb3 Be3 4.Qa4 c5 5.Qxa7 Qa5 6.f3 b6 7.Qb7 Qa7

> 8.dxe3 Ke7 9.e4 Kd6 10.Bg5 Nc6 11.Bd8 g6 12.Qb8+


The 'cook' is intentional. The diagram position would be illegal with 
this proofgame, since the 3-fold repetition happens already after the 
17th move by black.

The only solution is: 1. c4 g6 2. c5 Bh6 3. c6 Be3 4. cxb7 c5 5. Qb3 Qa5 
6. Qb6 axb6 7. f3 Qa7 8. dxe3 e6 9. e4 Ke7 10. Bg5+ Kd6 11. Bd8 Nc6 12. 
b8=Q+

Joost