[Retros] Long PG's ending in mate
elkies at math.harvard.edu
Tue Jul 7 18:10:01 EDT 2020
Mark Watkins (whose name you may recognize from
his work on Losing Chess) recently posed this question
on Chess Stackexchange:
Instead of an arbitrary bonus for ending in checkmate,
it's more naturally two questions: the well-known length task
for a PG with a unique solution, and the less well-known
length task for such a PG that moreover ends in checkmate.
Mark now asks me in e-mail (and accepted my offer to
ask his questions on this retros list):
1) Is Caillaud's capture-free https://pdb.dieschwalbe.de/P0002187
PG 38.5, #4495 in _Die Schwalbe_ 83 10/1983, 1. Pr.) also
the current length record for a sound proof game ending in checkmate?
2) What is the source of the 36.5 move proof game
Mark found it in his files and can neither reconstruct the attribution
nor locate it on PDB or elsewhere.
--Noam D. Elkies
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