Answers.Body: <p>I have done some initial research. This answer is available to edit for any who wishes to do improve the current standings. The shortest sequence for each mate in n is recorded by the number of plies needed to reach it. I have used <a href="https://lichess.org/analysis" rel="nofollow noreferrer">Lichess's</a> and <a href="https://www.chess.com/analysis" rel="nofollow noreferrer">chess.com's</a> opening analyzer's to aid me. The symbol #n will used to signify the relevant mate in n, and they will go in a descending order.</p>
  <p>#1: 3 Plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f3 e6 2. g4 Qh4#
  </code></pre>
  <p>#2: 3 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f3 e6 2. h3 Qh4+ 3. g3 Qxg3#
  </code></pre>
  <p>#3: 5 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f4 e6 2. Nf3 Be7 3. h3 Bh4+ 4. Nxh4 Qxh4+ 5. g3 Qxg3#
  </code></pre>
  <p>#4: 5 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. d3 e6 2. Kd2 Bd6 3. Ke3 Qg5+ 4. Ke4 Qe5+ 5. Kf3 Qf5+ 6. Ke3 Qf4#
  </code></pre>
  <p>#5: 5 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. e4 e5 2. f4 Bc5 3. h3 Qh4+ 4. g3 Qxg3+ 5. Ke2 Qf2+ 6. Kd3 Qd4+ 7. Ke2 Qxe4#
  </code></pre>
  <p>#6: 5 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. f4 e5 2. Kf2 exf4 3. h3 Qh4+ 4. Kf3 Qg3+ 5. Ke4 d5+ 6. Kxd5 Be6+ 7. Ke4 Nf6+ 8. Ke5 Nc6#
  </code></pre>
  <p>#7: 6 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. e3 e5 2. Bc4 Ke7 3. Qh5 Kf6 4. Qxf7+ Kg5 5. g4 g6 6. h4+ Kh6 7. g5+ Qxg5 8. hxg5+ Kxg5 9. Nf3+ Kg4 10. Rh4#
  </code></pre>
  <p>#8: 6 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. d4 e5 2. Kd2 Bb4+ 3. Ke3 Qg5+ 4. Kd3 e4+ 5. Kc4 b5+ 6. Kxb4 a5+ 7. Kc3 b4+ 8. Kb3 a4+ 9. Kc4 Ba6+ 10. Kxb4 Nc6+ 11. Ka3 Qe7+ 12. b4 Qxb4#
  </code></pre>
  <p>#9: 8 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. e4 d5 2. Qf3 d4 3. Nc3 Kd7 4. Bc4 Kc6 5. e5+ Kd7 6. Qd5+ Ke8 7. Qxf7+ Kd7 8. e6+ Kc6 9. Qf3+ Kb6 10. Na4+ Ka5 11. b4+ Kxb4 12. Qb3+ Ka5 13. Qb5#
  </code></pre>
  <p>#10: 5 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. d4 e5 2. Kd2 Bb4+ 3. Ke3 Qg5+ 4. Kd3 e4+ 5. Kc4 b5+ 6. Kxb4 a5+ 7. Kc3 b4+ 8. Kb3 a4+ 9. Kc4 Ba6+ 10. Kxb4 Nc6+ 11. Ka3 Qe7+ 12. b4 Qxb4#
  </code></pre>
  <p>#11: ?</p>
  <p>#12: ?</p>
  <p>#13: ?</p>
  <p>#14: ?</p>
  <p>#15: 8 Plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. d4 e5 2. Qd3 Ke7 3. Bg5+ Kd6 4. Bxd8 Nf6 5. Nf3 b6 6. Qb5 c5 7. dxc5+ Ke6 8. Ng5+ Kf5 9. Qd3+ e4 10. Nxe4 Ke5 11. Nxf6 Bb7 12. g3 g5 13. f4+ gxf4 14. Bh3 fxg3 15. Qc3+ Kf4 16. Qxg3#
  </code></pre>
  <p>#16: ?</p>
  <p>#17: 8 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. e4 d6 2. c3 Kd7 3. Qa4+ Ke6 4. Bc4+ Ke5 5. d4+ Kf6 6. e5+ dxe5 7. dxe5+ Kg6 8. Nf3 h6 9. Nh4+ Kh7 10. Qc2+ g6 11. Bxf7 Qd1+ 12. Kxd1 Bg4+ 13. f3 Bh5 14. Bxg6+ Kg7 15. Qf5 Nf6 16. exf6+ exf6 17. Qxh5 Be7 18. Nf5+ Kf8 19. Bxh6+ Rxh6 20. Qxh6+ Kg8 21. Nxe7#
  </code></pre>
  <p>#18: 10 plies</p>
  <pre><code>[FEN &quot;&quot;]
  
  1. d4 e5 2. Qd3 Ke7 3. Bg5+ Kd6 4. Bxd8 Nf6 5. dxe5+ Ke6 6. Qh3+ Kd5 7. Nc3+ Kc6 8. Qd3 b6 9. Qf3+ d5 10. exd6+ Kd7 11. dxc7 Nc6 12. O-O-O+ Bd6 13. Bxf6 a6 14.Qf4 Kxc7 15. Rxd6 Rb8 16. Nd5+ Kb7 17. Rxc6 Ka8 18. Nxb6+ Rxb6 19. Rxb6 Bb7 20. Qc7 Rb8 21. Bd4 Ka7 22. Rxa6+ Kxa6 23. e3#
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-08-12T08:40:14.513Z
Answers.Text: Just curious: Since you are a problemist like me, I assume you verified the values with a problemist software (not just Stockfish et al.), just to be 100% safe? Also just for the record, there are 120,921,506 games ( 9,132,484 distinct positions, see Google) after 6 halfmoves, this still seems to be manageable to brute-force.
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-08-11T21:27:15.323Z
Answers.LastActivityDate: 2022-01-23T18:52:50.773Z
Answers.LastEditDate: 2022-01-23T18:52:50.773Z
Answers.UserDisplayName: Rewan Demontay
Body: <p>Hauke Reddmann asked a <a href="https://chess.stackexchange.com/questions/34876/the-quickest-mate-in-n/34877#34877">cool question</a> about the quickest dual-free mates in n's from the starting position. But this is a rather limited scope. I wish to attack this idea from a different angle. What are the quickest <em>dualed</em> mates in n from the starting position?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-01-23T19:29:15.097Z
Comments.Text: What is a *dualed mate*?  Question would be more beneficial to future visitors if that was clearly defined.
Comments.UserDisplayName: SecretAgentMan
Tags: <problems><checkmate><records>
Title: The fastest dualed mates in n
ThreadText: # The fastest dualed mates in n
  
  (Asked by: username_0 on 2021-08-11)
  
  username_2 asked a [cool question](https://chess.stackexchange.com/questions/34876/the-quickest-mate-in-n/34877#34877) about the quickest dual-free mates in n's from the starting position. But this is a rather limited scope. I wish to attack this idea from a different angle. What are the quickest *dualed* mates in n from the starting position?
  
  **Tags:** problems, checkmate, records
  
  > **Comments:**
  > **username_1**: What is a *dualed mate*?  Question would be more beneficial to future visitors if that was clearly defined.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2021-08-11. Score: 1 | Accepted answer
  
  I have done some initial research. This answer is available to edit for any who wishes to do improve the current standings. The shortest sequence for each mate in n is recorded by the number of plies needed to reach it. I have used Lichess's and chess.com's opening analyzer's to aid me. The symbol #n will used to signify the relevant mate in n, and they will go in a descending order.
  #1: 3 Plies
  [FEN ""]
  
  1. f3 e6 2. g4 Qh4#
  
  #2: 3 plies
  [FEN ""]
  
  1. f3 e6 2. h3 Qh4+ 3. g3 Qxg3#
  
  #3: 5 plies
  [FEN ""]
  
  1. f4 e6 2. Nf3 Be7 3. h3 Bh4+ 4. Nxh4 Qxh4+ 5. g3 Qxg3#
  
  #4: 5 plies
  [FEN ""]
  
  1. d3 e6 2. Kd2 Bd6 3. Ke3 Qg5+ 4. Ke4 Qe5+ 5. Kf3 Qf5+ 6. Ke3 Qf4#
  
  #5: 5 plies
  [FEN ""]
  
  1. e4 e5 2. f4 Bc5 3. h3 Qh4+ 4. g3 Qxg3+ 5. Ke2 Qf2+ 6. Kd3 Qd4+ 7. Ke2 Qxe4#
  
  #6: 5 plies
  [FEN ""]
  
  1. f4 e5 2. Kf2 exf4 3. h3 Qh4+ 4. Kf3 Qg3+ 5. Ke4 d5+ 6. Kxd5 Be6+ 7. Ke4 Nf6+ 8. Ke5 Nc6#
  
  #7: 6 plies
  [FEN ""]
  
  1. e3 e5 2. Bc4 Ke7 3. Qh5 Kf6 4. Qxf7+ Kg5 5. g4 g6 6. h4+ Kh6 7. g5+ Qxg5 8. hxg5+ Kxg5 9. Nf3+ Kg4 10. Rh4#
  
  #8: 6 plies
  [FEN ""]
  
  1. d4 e5 2. Kd2 Bb4+ 3. Ke3 Qg5+ 4. Kd3 e4+ 5. Kc4 b5+ 6. Kxb4 a5+ 7. Kc3 b4+ 8. Kb3 a4+ 9. Kc4 Ba6+ 10. Kxb4 Nc6+ 11. Ka3 Qe7+ 12. b4 Qxb4#
  
  #9: 8 plies
  [FEN ""]
  
  1. e4 d5 2. Qf3 d4 3. Nc3 Kd7 4. Bc4 Kc6 5. e5+ Kd7 6. Qd5+ Ke8 7. Qxf7+ Kd7 8. e6+ Kc6 9. Qf3+ Kb6 10. Na4+ Ka5 11. b4+ Kxb4 12. Qb3+ Ka5 13. Qb5#
  
  #10: 5 plies
  [FEN ""]
  
  1. d4 e5 2. Kd2 Bb4+ 3. Ke3 Qg5+ 4. Kd3 e4+ 5. Kc4 b5+ 6. Kxb4 a5+ 7. Kc3 b4+ 8. Kb3 a4+ 9. Kc4 Ba6+ 10. Kxb4 Nc6+ 11. Ka3 Qe7+ 12. b4 Qxb4#
  
  #11: ?
  #12: ?
  #13: ?
  #14: ?
  #15: 8 Plies
  [FEN ""]
  
  1. d4 e5 2. Qd3 Ke7 3. Bg5+ Kd6 4. Bxd8 Nf6 5. Nf3 b6 6. Qb5 c5 7. dxc5+ Ke6 8. Ng5+ Kf5 9. Qd3+ e4 10. Nxe4 Ke5 11. Nxf6 Bb7 12. g3 g5 13. f4+ gxf4 14. Bh3 fxg3 15. Qc3+ Kf4 16. Qxg3#
  
  #16: ?
  #17: 8 plies
  [FEN ""]
  
  1. e4 d6 2. c3 Kd7 3. Qa4+ Ke6 4. Bc4+ Ke5 5. d4+ Kf6 6. e5+ dxe5 7. dxe5+ Kg6 8. Nf3 h6 9. Nh4+ Kh7 10. Qc2+ g6 11. Bxf7 Qd1+ 12. Kxd1 Bg4+ 13. f3 Bh5 14. Bxg6+ Kg7 15. Qf5 Nf6 16. exf6+ exf6 17. Qxh5 Be7 18. Nf5+ Kf8 19. Bxh6+ Rxh6 20. Qxh6+ Kg8 21. Nxe7#
  
  #18: 10 plies
  [FEN ""]
  
  1. d4 e5 2. Qd3 Ke7 3. Bg5+ Kd6 4. Bxd8 Nf6 5. dxe5+ Ke6 6. Qh3+ Kd5 7. Nc3+ Kc6 8. Qd3 b6 9. Qf3+ d5 10. exd6+ Kd7 11. dxc7 Nc6 12. O-O-O+ Bd6 13. Bxf6 a6 14.Qf4 Kxc7 15. Rxd6 Rb8 16. Nd5+ Kb7 17. Rxc6 Ka8 18. Nxb6+ Rxb6 19. Rxb6 Bb7 20. Qc7 Rb8 21. Bd4 Ka7 22. Rxa6+ Kxa6 23. e3#
  
  > **Comments:**
  > **username_2**: Just curious: Since you are a problemist like me, I assume you verified the values with a problemist software (not just Stockfish et al.), just to be 100% safe? Also just for the record, there are 120,921,506 games ( 9,132,484 distinct positions, see Google) after 6 halfmoves, this still seems to be manageable to brute-force.  
  
  ---
  
  