Where CAN'T the black King be?

Originally posted by BigDoggProblem
[fen]KR6/R7/8/4PP2/2pP2Pp/2P2B2/3B2Q1/4N3[/fen]

Find the three [b]unoccupied squares on the board that a Black King can not legally occupy.[/b]

Originally posted by cadwah
b4, b7, h5 and h1???

After a bit more thought I have concluded that I don't know how to solve this😛

Originally posted by BigDoggProblem
[fen]KR6/R7/8/4PP2/2pP2Pp/2P2B2/3B2Q1/4N3[/fen]

Find the three [b]unoccupied squares on the board that a Black King can not legally occupy.[/b]

Originally posted by sonhouse
don't see how the black king could be put on any of the 25 squares covered by the rooks for instance, so how can there be just 3?
Even if the board was upside down, the king couldn't occupy any of those squares so what gives?

b7 (adjacent to king) and b4 (impossible double check) are easy.
The final one is g5 as the checking bishop can't have moved to give check and a discovered check isn't possible (only a pawn on f4 could have interceded but that pawn would have been giving check).

As for the last move for the other answers given:
bK@h1:
0. Qf2(g3)xg2#

bK@h5:
0. hxg4+

The trick is to see what white's last move must have been. An instructive retrograde as always Bigdogg.

b4, b7, e2

what about f4 and e3 ?

f4 and e3 are possible - in both cases white's last move was a capture by the checking bishop.

Originally posted by David113
f4 and e3 are possible - in both cases white's last move was a capture by the checking bishop.

Originally posted by David113
b4, b7, e2

Originally posted by David113
b4, b7, e2

also h1

Originally posted by bjpcomet
also h1

Originally posted by BigDoggProblem
Nope. (Why?)