Answers.Body: <p>This is in fact possible in standard chess. I have found multiple possibilities in each of the following scenarios, so neither puzzle has a &quot;unique&quot; answer.</p>
  <p>Here is one that ends in checkmate:</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Be2 Q1f2 20. Kd1 Qxe2#
  </code></pre>
  <p>And here one that - more in the spirit of the question - ends in stalemate:</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Kd1 Bxa6 20. Kd2 Qxf1
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-04-29T09:43:56.543Z
Answers.LastActivityDate: 2023-04-29T09:43:56.543Z
Answers.UserDisplayName: koedem
Body: <p>Inspired by <a href="https://chess.stackexchange.com/questions/42027/longest-sequence-of-moves-where-whites-number-of-available-moves-decreases">this question</a>, koedem proved that, from the starting position, White's legal move amount can be decreased sequentially from 20 to 0 in 20 moves. However, doing so required some checks. I wondered if doing so was possible without check.</p>
  <p>In experimenting, I found a method to up the starting position to reduce to five legal moves without utilizing check.</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. a3 a6 2. f3 a5 3. h3 b6 4. b4 a4 5. b5 e5 6. g3 Bb4 7. g4 g5 8. Bg2 Bc3 9. Bf1 Qf6 10. f4 Qxf4 11. Rh2 Qxh2 12. h4 Qxg1 13. h5 d6 14. h6 Bxg4 15. e4 Bxd1
  </code></pre>
  <p>But I highly doubt that it is possible from the normal starting position (but is may be possible, I just think it unlikely; if so, it still counts as a valid answer). Is it possible in a Chess 960 position?</p>
  
Tags: <problems><records><mathematics><chess960>
Title: Is there a Chess 960 position in which White's moves can be decreased to zero without check?
ThreadText: # Is there a Chess 960 position in which White's moves can be decreased to zero without check?
  
  (Asked by: username_0 on 2023-04-29)
  
  Inspired by [this question](https://chess.stackexchange.com/questions/42027/longest-sequence-of-moves-where-whites-number-of-available-moves-decreases), username_1 proved that, from the starting position, White's legal move amount can be decreased sequentially from 20 to 0 in 20 moves. However, doing so required some checks. I wondered if doing so was possible without check.
  
  In experimenting, I found a method to up the starting position to reduce to five legal moves without utilizing check.
  
  ```
  [FEN ""]
  
  1. a3 a6 2. f3 a5 3. h3 b6 4. b4 a4 5. b5 e5 6. g3 Bb4 7. g4 g5 8. Bg2 Bc3 9. Bf1 Qf6 10. f4 Qxf4 11. Rh2 Qxh2 12. h4 Qxg1 13. h5 d6 14. h6 Bxg4 15. e4 Bxd1
  
  ```
  
  But I highly doubt that it is possible from the normal starting position (but is may be possible, I just think it unlikely; if so, it still counts as a valid answer). Is it possible in a Chess 960 position?
  
  **Tags:** problems, records, mathematics, chess960
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2023-04-29. Score: 2 | Accepted answer
  
  This is in fact possible in standard chess. I have found multiple possibilities in each of the following scenarios, so neither puzzle has a "unique" answer.
  
  Here is one that ends in checkmate:
  
  ```
  [FEN ""]
  
  1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Be2 Q1f2 20. Kd1 Qxe2#
  
  ```
  
  And here one that - more in the spirit of the question - ends in stalemate:
  
  ```
  [FEN ""]
  
  1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Kd1 Bxa6 20. Kd2 Qxf1
  
  ```
  
  
  ---
  
  