[Retros] FW: FW: distance-PG-

Noam Elkies elkies at math.harvard.edu
Sat Sep 10 21:56:32 EDT 2016


Nicolas Dupont <Nicolas.Dupont at univ-lille1.fr> writes:

> Without ep (nor final checkmate), my best bound is reached via the  
> following sequence:
>
> 1. Pe2-e4   Ph7-h5     2. Dd1xh5   Pa7-a5     3. Dh5xa5   Th8xh2
> 4. Da5xc7   Th2-h8     5. Th1xh8   Ta8xa2     6. Dc7-h2   Ta2-a8
> 7. Ta1-a6   Dd8-a5     8. Ta6-h6   Da5-h5     9. Ff1-a6   Dh5-d1
>
> (63,23,0) in 9.0 => move-length average a bit over 5.30.

This fine record is also tantalizingly close to checkmate.
Does it remain sound if the final three moves are changed to

7. Ta1-a7   Dd8-a5     8. Ff1-a6   Da5-h5     9. Re1-f1   Dh5-d1#

?  This loses 5 units (last three White moves are (7,5,0) instaead of
(12,5,0) but still comes to (58,23,0) = 90.52691... which makes the
per-(half-)move average 5.02927...  One might even try to make the
7th move Ta1xa8, raising the orthogonal count from 58 to 59 and the
average to 5.084828..


More information about the Retros mailing list