Answers.Body: <p>27 piles</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. c4 a5 2. h4 h5 3. Qa4 Ra6 4. Qxa5 Rah6 5. Qxc7 f6 6. Qxd7+ Kf7 7. Qxb7 Qd3 8. Qxb8 Qh7 9. Qxc8 Kg6 10. g3 Kf7 11. Bg2 Kg6 12. Nh3 Kf7 13. Qe6+ Kg6 14. O-O 1/2-1/2
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-02-29T03:33:05.137Z
Answers.Text: But this game (based on a well-known help stalemate in 19 plies) doesn't satisfy the condition because White had many stalemating moves other than 0-0.
Answers.UserDisplayName: Noam D. Elkies
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-02-29T03:34:04.147Z
Answers.Text: @NoamD.Elkies I was just about to say as such, thank you. Notice the word 'must' in the question. Castling is not needed to induce the stalemate here.
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-02-29T00:37:26.370Z
Answers.LastActivityDate: 2024-02-29T00:37:26.370Z
Answers.UserDisplayName: Lucenaposition
Answers.Body: <p>I’ve found a way to reduce the count down to <strong>31 plies.</strong></p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f4 e5 2. fxe5 d6 3. exd6 Qg5 dxc7 Qxg2 5. cxb8=Q Qxh2 Qxa7 Qxg1 7. Qxa8 Qg2 8. Bxg2 g5 9. Qxb7 g4 10. Qxc8+ Ke7 11. Qxf8+ Ke6 12. Qxf7+ Ke5 13. Qxg8 Kf4 14. Qxh8 h5 15. Qxh5 Kg3 16. O-O
  </code></pre>
  <p>White has only two non-capturing moves, the first pawn move and casting. Black uses up all of their moves without rest. Therefore, I think that 31 plies may be optimal unless a pawn capture can be shaved off.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-05-22T16:15:53.083Z
Answers.LastActivityDate: 2021-01-26T17:20:27.510Z
Answers.LastEditDate: 2021-01-26T17:20:27.510Z
Answers.UserDisplayName: Rewan Demontay
Body: <p>It is <a href="https://chess.stackexchange.com/questions/28797/what-is-the-fastest-way-to-reach-stalemate">known</a> what the fastest stalemate is. But what but is the fastest possible stalemate in which castling must be the last move?</p>
  <p><strong>33 plies</strong> is my best result so far.</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. e4 h5 2. Qxh5 d6 3. Qxh8 Bh3 4. Qxg7 Bxg2 5. Qxg8 Bxf1 6. Qxf7+ Kd7 7. Qxf8 Kc6 8. Qxd8 e5 9. Qxd6+ Kb5 10. Qxc7 Bd3 11. Qxb8 Bxc2 12. Qxa8 Bd1 13. Qxa7 Kc4 14. Qxb7 Kd3 15. Nf3 Kc2 16. Qb3+ Kxc1 17. O-O
  </code></pre>
  <p>Castling for a pin isn’t the only possible motivation though. Here is <strong>another 33 plies</strong> sequence that shows motivation in protecting pieces and guarding squares.</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f4 e5 2. fxe5 d6 3. exd6 Qg5 4. dxc7 Ke7 5. cxb8=Q Qxg2 6. Qxc8 Qxh2 7. Qxa8 Qxg1 8. Qxa7 g5 9. Qxb7+ Ke6 10. Qxf7+ Ke5 11. Qxf8 Qh2 12. Qxg8 Qh5 13. Qxh8+ Kf4 14. Qxh7 Kg4 15. Bg2 Kg3 16. Qxh5 g4 17. O-O
  </code></pre>
  
Tags: <problems><castling><stalemate><records>
Title: What is the fastest possible stalemate by castling?
ThreadText: # What is the fastest possible stalemate by castling?
  
  (Asked by: username_0 on 2020-05-22)
  
  It is known what the fastest stalemate is. But what but is the fastest possible stalemate in which castling must be the last move?
  33 plies is my best result so far.
  [FEN ""]
  
  1. e4 h5 2. Qxh5 d6 3. Qxh8 Bh3 4. Qxg7 Bxg2 5. Qxg8 Bxf1 6. Qxf7+ Kd7 7. Qxf8 Kc6 8. Qxd8 e5 9. Qxd6+ Kb5 10. Qxc7 Bd3 11. Qxb8 Bxc2 12. Qxa8 Bd1 13. Qxa7 Kc4 14. Qxb7 Kd3 15. Nf3 Kc2 16. Qb3+ Kxc1 17. O-O
  
  Castling for a pin isn’t the only possible motivation though. Here is another 33 plies sequence that shows motivation in protecting pieces and guarding squares.
  [FEN ""]
  
  1. f4 e5 2. fxe5 d6 3. exd6 Qg5 4. dxc7 Ke7 5. cxb8=Q Qxg2 6. Qxc8 Qxh2 7. Qxa8 Qxg1 8. Qxa7 g5 9. Qxb7+ Ke6 10. Qxf7+ Ke5 11. Qxf8 Qh2 12. Qxg8 Qh5 13. Qxh8+ Kf4 14. Qxh7 Kg4 15. Bg2 Kg3 16. Qxh5 g4 17. O-O
  
  **Tags:** problems, castling, stalemate, records
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_0 on 2020-05-22. Score: 5 | Accepted answer
  
  I’ve found a way to reduce the count down to 31 plies.
  [FEN ""]
  
  1. f4 e5 2. fxe5 d6 3. exd6 Qg5 dxc7 Qxg2 5. cxb8=Q Qxh2 Qxa7 Qxg1 7. Qxa8 Qg2 8. Bxg2 g5 9. Qxb7 g4 10. Qxc8+ Ke7 11. Qxf8+ Ke6 12. Qxf7+ Ke5 13. Qxg8 Kf4 14. Qxh8 h5 15. Qxh5 Kg3 16. O-O
  
  White has only two non-capturing moves, the first pawn move and casting. Black uses up all of their moves without rest. Therefore, I think that 31 plies may be optimal unless a pawn capture can be shaved off.
  
  
  ---
  
  ### Answer by username_1 on 2024-02-29. Score: 2
  
  27 piles
  [FEN ""]
  
  1. c4 a5 2. h4 h5 3. Qa4 Ra6 4. Qxa5 Rah6 5. Qxc7 f6 6. Qxd7+ Kf7 7. Qxb7 Qd3 8. Qxb8 Qh7 9. Qxc8 Kg6 10. g3 Kf7 11. Bg2 Kg6 12. Nh3 Kf7 13. Qe6+ Kg6 14. O-O 1/2-1/2
  
  > **Comments:**
  > **username_2**: But this game (based on a well-known help stalemate in 19 plies) doesn't satisfy the condition because White had many stalemating moves other than 0-0.  
  > **username_0**: @NoamD.Elkies I was just about to say as such, thank you. Notice the word 'must' in the question. Castling is not needed to induce the stalemate here.  
  
  ---
  
  