# Where CAN'T the black King be?

BigDoggProblem
Posers and Puzzles 11 Dec '06 22:42
1. BigDoggProblem
11 Dec '06 22:42

Find the three unoccupied squares on the board that a Black King can not legally occupy.
¯\_(^.^)_/¯
11 Dec '06 22:521 edit
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]
b4, b7, h5 and h1???

After a bit more thought I have concluded that I don't know how to solve this😛
3. BigDoggProblem
11 Dec '06 23:252 edits
b4, b7, h5 and h1???

After a bit more thought I have concluded that I don't know how to solve this😛
You are close to the right answer. Two of the four squares you listed are legal squares; the other two are not.
4. sonhouse
Fast and Curious
12 Dec '06 05:37
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]
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?
5. BigDoggProblem
12 Dec '06 05:44
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?
Checkmate is legal.
6. XanthosNZ
Cancerous Bus Crash
12 Dec '06 08:571 edit
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.
7. 12 Dec '06 09:31
b4, b7, e2
8. 12 Dec '06 10:08
what about f4 and e3 ?
9. 12 Dec '06 10:202 edits
f4 and e3 are possible - in both cases white's last move was a capture by the checking bishop.
10. XanthosNZ
Cancerous Bus Crash
12 Dec '06 10:31
Originally posted by David113
f4 and e3 are possible - in both cases white's last move was a capture by the checking bishop.
Ah missed that.
11. BigDoggProblem
12 Dec '06 16:13
Originally posted by David113
b4, b7, e2
This is the answer the judges were looking for.
12. 15 Dec '06 09:11
Originally posted by David113
b4, b7, e2
ahh yes the king cannot be on a square where it would have been in check from 2 different pieces (that wasn't part of a discovered check move)
13. 16 Dec '06 02:34
also h1
14. BigDoggProblem