[Retros] recent improvements

[Mario Richter]

Joost wrote:

> >     1 Pe7xd8=N

> 

> I find this hard to believe. Francois Labelle (using my computer) did an 

> exhaustive search for all 11-ply games to see if there were any games 

> determined by the last move, and the only one found was Peter Roessler's 

> 6. g7xf8=N#


The line above only says that there is only one *correct* (i.e. single-
solution) SPG in 11 plies which ends with Pe7xd8=N#.

There are other games in 11 plies ending with Pe7xd8=N#, e.g.
1.a4 b6 2.e4 d6 3.e5 Ke8-d7 4.exd6 Kd7-c6 5.dxe7 Kc6-b7 6.exd8=N#,
but they do not constitute are correct SPG ...

Regards,

  mario