user18312: Sometime ago, a friend showed me a position where he had the Black king removed. The goal was to find where is the Black king using some pretty weird reasoning.
There were only a few pieces on the board and they were quite close to each other in the bottom left corner of the board. Mostly likely, each side has two pawns each, and, maybe two pieces. I'm almost sure that the White king was in double check.
Here are more details that in a spoiler due to hinting at the solution)

The solution (very approximately) is first to find who's move it is. It is obviously White's because of the check, and then from that deduce what Black's last move was. From that, you deduce the king's position. The reasoning was more complicated than the, as it required to go two or three moves backward. This is the gist of the problem.

I have tried to remember the problem, but I can't. Does anyone know a "where is the black king" problem?

user15989: What leaps to mind is Raymond Smullyan's problem, and it's to find the White king but possibly it. A retro classic (and one of the few good ones he made.)
8/8/8/1r1b4/B7/8/8/3k4 w - - 0 1

(1+3) Where is the white king?
(Raymond Smullyan, Manchester Guardian, 1957)

18312: <p>Sometime ago, a friend showed me a position where he had the Black king removed. The goal was to find where is the Black king using some pretty weird reasoning.</p>
<p>There were only a few pieces on the board and they were quite close to each other in the bottom left corner of the board. Mostly likely, each side has two pawns each, and, maybe two pieces. I'm almost sure that the White king was in double check.</p>
<p><strong>Here are more details that in a spoiler due to hinting at the solution)</strong></p>
<blockquote class="spoiler">
<p>The solution (very approximately) is first to find who's move it is. It is obviously White's because of the check, and then from that deduce what Black's last move was. From that, you deduce the king's position. The reasoning was more complicated than the, as it required to go two or three moves backward. This is the gist of the problem.</p>
</blockquote>
<p>I have tried to remember the problem, but I can't. Does anyone know a &quot;where is the black king&quot; problem?</p>
 15989: <p>What leaps to mind is Raymond Smullyan's problem, and it's to find the White king but possibly it. A retro classic (and one of the few good ones he made.)</p>
<pre><code>8/8/8/1r1b4/B7/8/8/3k4 w - - 0 1
</code></pre>
<p>(1+3) Where is the white king?</p>
<p>(Raymond Smullyan, <em>Manchester Guardian</em>, 1957)</p>
