user15511: I was thinking about a situation on a chessboard. You can call it a riddle, but I am not sure whether it is solvable or not.
Let's say that there are more than 5 pieces for both Black and White, including the kings, on a chessboard and it is White's turn.
The Riddle: Is it possible to arrange all the pieces on the chessboard, in such a manner, so that, for every possible move by White, the Black king gets checkmated? Can you construct such a position?

What I've thought so far:
Since King can't give a checkmate (apart from exceptional cases of a two queens/two rook mate), the White king should be immovable. Otherwise, the criteria of the riddle can't be fulfilled. But thinking about it this way, I can't set up any position that meets the criteria of my riddle.=

user15543: This is a very easy concept to construct, and it has already been done on Tim Krabbe's site as noted by Ian Bush in a comment. Here are the current records, i.e. the highest that has been constructed by chess problemists so far.
I found two cases of 55 forced mates with promoted pieces in Tim Krabbe’s Diary Entry #383.
[Title "Ludwig Zagler, Feenschach 1972, 55 Forced Mates"]
[FEN "1rB1Q1Q1/1PRQ3Q/2b2k2/2pQ1N1Q/4KRPp/5N2/1R6/B3nn1b w - - 0 1"]


[Title "Sampsa Lahtonen, Tim Krabbe's Website Diary Entry #383 2008, 55 Forced Mates"]
[FEN "B3n1bb/1R6/4pN2/4KRPp/2pQ1N1Q/2b2k2/1PRQ3Q/1rB1Q1Q1 w - - 0 1"]

Without promoted pieces, the record is 29, as Krabbe reported in his Diary Entry #334.
[Title "Harold Holgate Cross, The Problemist FCS 4/1936, 2251"]
[fen "8/1b6/p1N5/P1r5/P3KPr1/QBk1NRP1/P2R1P2/4B3 w KQkq - 0 1"]


user24790: [FEN "K3k2n/7n/rr1R3N/7n/8/8/4BQ2/4R3 w - - 0 1"]

1. Bxa6#

Here is a much more simple situation where White only has only one legal move, which is a discovered checkmate.

15511: <p>I was thinking about a situation on a chessboard. You can call it a riddle, but I am not sure whether it is solvable or not.</p>
<p>Let's say that there are more than 5 pieces for both Black and White, including the kings, on a chessboard and it is White's turn.</p>
<p>The Riddle: Is it possible to arrange all the pieces on the chessboard, in such a manner, so that, for <strong>every possible move</strong> by White, the Black king gets checkmated? Can you construct such a position?</p>
<hr />
<p>What I've thought so far:</p>
<p>Since King can't give a checkmate (apart from exceptional cases of a two queens/two rook mate), the White king should be immovable. Otherwise, the criteria of the riddle can't be fulfilled. But thinking about it this way, I can't set up any position that meets the criteria of my riddle.=</p>
 15543: <p>This is a very easy concept to construct, and it has already been done on Tim Krabbe's site as noted by Ian Bush in a comment. Here are the current records, i.e. the highest that has been constructed by chess problemists so far.</p>
<p>I found two cases of <strong>55</strong> forced mates with promoted pieces in Tim Krabbe’s <a href="https://timkr.home.xs4all.nl/chess2/diary.htm" rel="noreferrer">Diary Entry #383</a>.</p>
<pre><code>[Title &quot;Ludwig Zagler, Feenschach 1972, 55 Forced Mates&quot;]
[FEN &quot;1rB1Q1Q1/1PRQ3Q/2b2k2/2pQ1N1Q/4KRPp/5N2/1R6/B3nn1b w - - 0 1&quot;]
</code></pre>
<hr />
<pre><code>[Title &quot;Sampsa Lahtonen, Tim Krabbe's Website Diary Entry #383 2008, 55 Forced Mates&quot;]
[FEN &quot;B3n1bb/1R6/4pN2/4KRPp/2pQ1N1Q/2b2k2/1PRQ3Q/1rB1Q1Q1 w - - 0 1&quot;]
</code></pre>
<p>Without promoted pieces, the record is 29, as Krabbe reported in his <a href="https://timkr.home.xs4all.nl/chess2/diary_17.htm" rel="noreferrer">Diary Entry #334.</a></p>
<pre><code>[Title &quot;Harold Holgate Cross, The Problemist FCS 4/1936, 2251&quot;]
[fen &quot;8/1b6/p1N5/P1r5/P3KPr1/QBk1NRP1/P2R1P2/4B3 w KQkq - 0 1&quot;]
</code></pre>
 24790: <pre><code>[FEN &quot;K3k2n/7n/rr1R3N/7n/8/8/4BQ2/4R3 w - - 0 1&quot;]

1. Bxa6#
</code></pre>
<p>Here is a much more simple situation where White only has only one legal move, which is a discovered checkmate.</p>
