[Retros] yet another 8th rank mate

[andrew buchanan]

Here's an interesting find. With Black defenders everywhere, it doesn't
look as if it can be mate, but it is.

rnb1Bbnr/ppp3pp/3q1pk1/3Q4/8/8/PPP1PPPP/RNB1KBNR
PG in 5.5

(also a record if promoting to Q instead of B).

Cheers,
Andrew.