Answers.Body: <p>The best I could come up with is 7 moves, I don't believe it could take much longer, because with 4 queens there's not as much freedom as with 2, I cannot put black king in the middle of the board when capturing black queens while keeping king in check:</p>
  
  <pre><code>3q4/q7/q7/q7/8/8/8/k1K4Q w - - 0 1
  </code></pre>
  
  <p>And I made it nice as you asked -- the first move it not a capture! =)</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-22T22:05:26.037Z
Answers.Text: This is 7 moves? It looks like three: Kc2+ Ka2 Qb1+ Ka3 Qb3#.
Answers.UserDisplayName: D M
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-22T23:08:26.057Z
Answers.Text: @DM do you have any chess engine? load this up, ask to analyze...
Answers.UserDisplayName: lenik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-22T23:57:31.100Z
Answers.Text: @DM ok, from another posts, I can see the concept of sacrificing the queen to postpone the mate is somehow unfamiliar to you. so here it is: Kc2+ Qg2 -- start from here and go up to 7 moves =)
Answers.UserDisplayName: lenik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-23T01:28:22.210Z
Answers.Text: OK, I'm wrong, you're right.
Answers.UserDisplayName: D M
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-23T07:04:58.730Z
Answers.Text: @DM no worries, everyone is wrong sometimes =)
Answers.UserDisplayName: lenik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-07-21T12:15:33.823Z
Answers.LastActivityDate: 2018-07-25T23:01:52.247Z
Answers.LastEditDate: 2018-07-25T23:01:52.247Z
Answers.UserDisplayName: lenik
Answers.Body: <p>This max-DTZ position is mate in 8, but probably also a dead-end because it seems hard to improve starting here.</p>
  
  <pre><code>[FEN "7q/4q1q1/8/8/3q2Q1/1K6/8/1k6 w - - 0 1"]
  
  1. Qf5+ Qde4 2. Qf1+ Qe1 3. Qd3+ Ka1 4. Qa6+ Qa5
  5. Qxa5+ Qa3+ 6. Qxa3+ Kb1 7. Qa2+ Kc1 8. Qc2#
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-08-12T11:03:14.397Z
Answers.Text: Very nice position ! (+1)
Answers.UserDisplayName: Peter
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-08-12T02:01:03.403Z
Answers.LastActivityDate: 2018-08-12T02:01:03.403Z
Answers.UserDisplayName: Niklas
Body: <p>What is the longest way to checkmate with 1 queen against 4 queens, with no other pieces on the board?</p>
  
  <p>Since there are 13 moves long games with a queen vs two queens, I conjecture this should be possible also for this certain endgame, but I am not sure. The maximum position I know has the disadvantage that the first move is a capture. It would be nice if the first move is not a capture.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-03-10T22:52:43.013Z
Comments.Text: I may have misread your question. I interpreted it as asking for the max DTM for the 4-queen side against the 1-queen side. Were you actually asking about the longest mate for the 1-queen side against the 4-queen side? Then your conjecture makes more sense to me.
Comments.UserDisplayName: ETD
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-03-11T17:08:27.723Z
Comments.Text: Yes, I search the maximum DTM where ONE queen WINS against 4 queens and the first move is no capture.
Comments.UserDisplayName: Peter
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-03-11T21:50:50.870Z
Comments.Text: Some info that doesn't speak directly to your conjecture, but is the most relevant I know: [Bourzutschky et al.](http://centaur.reading.ac.uk/4524/1/2005a_TCS_BTH_Chess_Endgames_6-man_Data_and_Strategy_-_preprint.pdf) indicate a max depth-to-*conversion* of 10 moves (see p.11) for a position where KQ-to-move wins against three queens.
Comments.UserDisplayName: ETD
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-03-11T23:19:17.967Z
Comments.Text: Unfortunately, no example position is given. Otherwise, it might be possible to derivate an example with 4 queens as well.
Comments.UserDisplayName: Peter
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-02-12T09:20:50.843Z
Comments.Text: presumably there are also kings on the board.
Comments.UserDisplayName: hkBst
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-06-29T13:15:58.297Z
Comments.Text: @Peter can you post FEN for 13 moves for QvsQQ ?
Comments.UserDisplayName: lenik
Tags: <endgame><checkmate><tablebases><records><queen-endgame>
Title: Longest way to mate with 1 queen against 4 queens
ThreadText: # Longest way to mate with 1 queen against 4 queens
  
  (Asked by: username_0 on 2015-03-10)
  
  What is the longest way to checkmate with 1 queen against 4 queens, with no other pieces on the board?
  
  Since there are 13 moves long games with a queen vs two queens, I conjecture this should be possible also for this certain endgame, but I am not sure. The maximum position I know has the disadvantage that the first move is a capture. It would be nice if the first move is not a capture.
  
  **Tags:** endgame, checkmate, tablebases, records, queen-endgame
  
  > **Comments:**
  > **username_1**: I may have misread your question. I interpreted it as asking for the max DTM for the 4-queen side against the 1-queen side. Were you actually asking about the longest mate for the 1-queen side against the 4-queen side? Then your conjecture makes more sense to me.  
  > **username_0**: Yes, I search the maximum DTM where ONE queen WINS against 4 queens and the first move is no capture.  
  > **username_1**: Some info that doesn't speak directly to your conjecture, but is the most relevant I know: [Bourzutschky et al.](http://centaur.reading.ac.uk/4524/1/2005a_TCS_BTH_Chess_Endgames_6-man_Data_and_Strategy_-_preprint.pdf) indicate a max depth-to-*conversion* of 10 moves (see p.11) for a position where KQ-to-move wins against three queens.  
  > **username_0**: Unfortunately, no example position is given. Otherwise, it might be possible to derivate an example with 4 queens as well.  
  > **username_2**: presumably there are also kings on the board.  
  > **username_3**: @username_0 can you post FEN for 13 moves for QvsQQ ?  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_5 on 2018-08-12. Score: 7
  
  This max-DTZ position is mate in 8, but probably also a dead-end because it seems hard to improve starting here.
  
  ```
  [FEN "7q/4q1q1/8/8/3q2Q1/1K6/8/1k6 w - - 0 1"]
  
  1. Qf5+ Qde4 2. Qf1+ Qe1 3. Qd3+ Ka1 4. Qa6+ Qa5
  5. Qxa5+ Qa3+ 6. Qxa3+ Kb1 7. Qa2+ Kc1 8. Qc2#
  
  ```
  
  > **Comments:**
  > **username_0**: Very nice position ! (+1)  
  
  ---
  
  ### Answer by username_3 on 2018-07-21. Score: 6
  
  The best I could come up with is 7 moves, I don't believe it could take much longer, because with 4 queens there's not as much freedom as with 2, I cannot put black king in the middle of the board when capturing black queens while keeping king in check:
  
  ```
  3q4/q7/q7/q7/8/8/8/k1K4Q w - - 0 1
  
  ```
  
  And I made it nice as you asked -- the first move it not a capture! =)
  
  > **Comments:**
  > **username_4**: This is 7 moves? It looks like three: Kc2+ Ka2 Qb1+ Ka3 Qb3#.  
  > **username_3**: @DM do you have any chess engine? load this up, ask to analyze...  
  > **username_3**: @DM ok, from another posts, I can see the concept of sacrificing the queen to postpone the mate is somehow unfamiliar to you. so here it is: Kc2+ Qg2 -- start from here and go up to 7 moves =)  
  > **username_4**: OK, I'm wrong, you're right.  
  > **username_3**: @DM no worries, everyone is wrong sometimes =)  
  
  ---
  
  