[Retros] Pawn to-the-8th-rank mates

[andrew buchanan]

Here are my latest ones...

(1) A couple of improvements:

bR
rnb1kbnr/p2ppppp/1p6/q7/3Q4/8/P1PRPPPP/1r2KBNR
PG in 7.0
(and sim for Q)

bN
rnb1kbnr/1p1ppppp/p7/8/P7/3PR3/2PKPPPP/1nBNQBNR
PG in 8.0


(2) Some new ones:

bxaR
R3kbnr/p1pnpppp/3q4/3p4/Q7/8/PP1PPPPP/RNB1KBNR
PG in 5.5
(and sim for Q)

cxbR
rnb1kbnr/pp1ppppp/8/q7/8/3PB3/PP1NPPPP/1r2KBNR
PG in 6.0
(this is virtually identical to axb1R#)
(and sim for Q)

exfR
rnbqkRnr/pppp1p1p/6p1/8/8/B7/P1P1PPPP/RN1QKBNR
PG in 5.5
(and sim for Q)

fxgR
rnbq1kR1/pppp2R1/8/3rp3/8/8/PPPPPPP1/RNBQKBN1
PG in 6.5
(and sim for Q)