[Retros] N2Ai: 7Qs+2Rs

[Noam Elkies]

Alain BROBECKER <abrobecker at yahoo.com> writes:


> The computer at last found a 7Q+2R position for N2Ai.

> There won't be much of them i think.

> I don't know if it's more interesting than

> previous 8Qs+1R position


Neat -- but wait, what about double checks?

Come to think of it the one-Rook problem has such cooks as well
(http://www.janko.at/Retros/d.php?ff=3R1k2/1Q6/5KQ1/2Q5/Q7/4Q2Q/5Q2/Q7,
http://www.janko.at/Retros/d.php?ff=3R1k2/1Q6/5KQ1/2Q5/Q7/4Q2Q/5Q2/Q7)
and this one does too (Kb4/kb1: Q7/7Q/3Q1Q2/1Q6/1K4Q1/4Q3/R7/1kR5).

Did you also look for positions with a Bishop in the corner?
A Bishop on a1 can't give check even once unless it's discovered check,
so b2/c3 are already dealt with and each of the five squares d4-h8
need only be covered once more.  No double-check worries either
unless you also try to replace one of the remaining Q's by a Rook.

NDE