[Retros] recent improvements

[andrew buchanan]

Hi folks,

(1) A shorter example of an "R yes Q no" PG
rnR1kbnr/p2ppppp/8/1q6/8/8/P1P1PPPP/RNB1KBNR
PG in 5.5
But can't replace Rc8 with Q, or PG is unsound
Note removal of dual in wP trajectory

(2) Slightly improved version of hR
rnbqk2Q/pppppp2/8/8/6n1/P5r1/1PPPPPP1/RNBQKBN1
PG in 6.5
(similarly with Qh8)

(3) Improved version of fN
rnb1kbnr/ppp1pppp/8/5q2/3P4/4K1P1/PPPQP2P/RNB2nNR
PG in 7.0

(4) Improved version of fxgN
rnb1kbn1/pppp1pp1/3Rp3/8/7q/4PK2/PPPPB1P1/RNB3n1
PG in 8.0

However, Francois Labelle's (& Mario Richter's?) programs have not spoken in
this discussion. Tasks of this kind ought to be tractable in the same way
that massacre positions proved to be. Basically, ignore any move where a
promotion cannot be achieved in the number of moves remaining.

Cheers,
Andrew.

Cheers,
Andrew.