user17920: In a standard opening position in chess, imagine that all Black pieces are removed except for the king and pawns.
[FEN "4k3/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

What is the shortest forced mate, assuming White starts?
I don't know the answer to this but it seems like a fun piece of chess trivia if it is solvable.

user18168: Stockfish took a long time with this one, but with some help it eventually got to here.
Looks like it's approximately checkmate in 15 from your position. By move 9 (following Stockfish recommendations) it finds a checkmate in 6. Here's what Stockfish says is the best line:
[FEN "4k3/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

1. c3 b5 2. Qb3 c6 3. Qa3 a5 4. Qxa5 e5 5. Qc7 f6 6. Qc8+ Ke7 7. Qg8 e4 8. Qxg7+ Ke6 9. g3 f5 10. d4 e3 11. Bh3 b4 12. Bxf5+ Kxf5 13. Qf7+ Kg5 14. Bxe3+ Kg4 15. f3#

Here's a sample game, me vs Stockfish. Took me 18 moves: https://lichess.org/AJFXfWmCQB5I
And another, also 18 moves: https://lichess.org/Ibno7F6cdfhT
I missed some sequences both times.

user17920: Having run stockfish for a couple of days, I can confirm there is at least a mate in 15.


17920: <p>In a standard opening position in chess, imagine that all Black pieces are removed except for the king and pawns.</p>
<pre><code>[FEN &quot;4k3/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1&quot;]
</code></pre>
<p>What is the shortest forced mate, assuming White starts?</p>
<p>I don't know the answer to this but it seems like a fun piece of chess trivia if it is solvable.</p>
 18168: <p>Stockfish took a long time with this one, but with some help it eventually got to <a href="https://lichess.org/study/FJKaViJU" rel="nofollow noreferrer">here.</a></p>

<p>Looks like it's <em>approximately</em> checkmate in 15 from your position. By move 9 (following Stockfish recommendations) it finds a checkmate in 6. Here's what Stockfish says is the best line:</p>

<pre><code>[FEN "4k3/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

1. c3 b5 2. Qb3 c6 3. Qa3 a5 4. Qxa5 e5 5. Qc7 f6 6. Qc8+ Ke7 7. Qg8 e4 8. Qxg7+ Ke6 9. g3 f5 10. d4 e3 11. Bh3 b4 12. Bxf5+ Kxf5 13. Qf7+ Kg5 14. Bxe3+ Kg4 15. f3#
</code></pre>

<p>Here's a sample game, me vs Stockfish. Took me 18 moves: <a href="https://lichess.org/AJFXfWmCQB5I" rel="nofollow noreferrer">https://lichess.org/AJFXfWmCQB5I</a></p>

<p>And another, also 18 moves: <a href="https://lichess.org/Ibno7F6cdfhT" rel="nofollow noreferrer">https://lichess.org/Ibno7F6cdfhT</a></p>

<p>I missed some sequences both times.</p>
 17920: <p>Having run stockfish for a couple of days, I can confirm there is at least a mate in 15.</p>

<p><a href="https://i.stack.imgur.com/M93U6.png" rel="noreferrer"><img src="https://i.stack.imgur.com/M93U6.png" alt="enter image description here"></a></p>
