Answers.Body: <p>I bid <strong>200 moves</strong>, with two moves added courtesy of an improvement by @James Martin.</p>
  <pre><code>R4Q2/2Q4Q/4Q3/1Q4QB/3Q3b/Q4R1q/2Q1rprN/2nbBKNk w - - 0 1 
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-14T18:09:32.553Z
Answers.Text: Very nice!! How about replacing the black pawn on g3 by a black bishop on h4, and then adding a white bishop on h5? I think that gains a couple!
Answers.UserDisplayName: James Martin
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-14T19:45:48.647Z
Answers.Text: @JamesMartin Indeed it gains one, thanks. Just shy of 200...
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T15:20:40.623Z
Answers.Text: Presumably I'm overlooking something obvious, but why doesn't it gain 2? Newly possible: Be8, Bf7, Bg6, Bg4, Qxg2+, Rxh3. No longer possible: Qgh5, Qhh5, Qhh4, Qhxh3.
Answers.UserDisplayName: James Martin
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T20:19:37.277Z
Answers.Text: @JamesMartin You’re right, I miscounted. Needed a fresh look, it seems.
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T21:59:01.477Z
Answers.Text: What's White's checkmate after 1...Qxf3?
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T22:50:03.987Z
Answers.Text: @Allure White is the one *getting* checkmated by Black, not the other way around.
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T22:54:09.193Z
Answers.Text: Thanks. What's Black's checkmate after 1. Rxh3?
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T23:22:12.023Z
Answers.Text: @Allure fxe1=Q#/R#.
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-16T00:00:03.417Z
Answers.Text: Thanks, was only looking at Rxg1# for some reason.
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-14T02:27:36.773Z
Answers.LastActivityDate: 2023-10-15T20:19:18.107Z
Answers.LastEditDate: 2023-10-15T20:19:18.107Z
Answers.UserDisplayName: Rewan Demontay
Answers.Body: <p>I only write this as an answer (it isn't) as this is an invaluable source for one-move records, with citations (surely more questions on CSE apply). Since the positions are rather old some records might be broken (or will be broken by Rewan after he fought through the linked site's Excel table).</p>
  <p><a href="http://www.skcaissa.de/einzueger.htm" rel="nofollow noreferrer">Sorry, German only</a></p>
  <p>According to the table (if I interpret the terminology correctly) this would be &quot;erzwungene Mattduldungen&quot;. You can search this simply in the SCHWALBE PDB by entering this term as STIP= search. Since even &quot;voluntary&quot; instead of &quot;forced&quot; gives only a record of 201 (P1179075) under this side condition (&quot;With promoted material, legal&quot; - seven subtypes are listed), I guess Rewan's record stands. Allowing illegal positions, 255 (P0005619). Forbidding promoted pieces, 135 (P1178928). Since this peculiar record is missing, I suggest Rewan updates the PDB.</p>
  <p>(off to alert MatPlusForum)</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-10-15T07:55:33.213Z
Answers.LastActivityDate: 2023-10-15T07:55:33.213Z
Answers.UserDisplayName: Hauke Reddmann
Body: <p>Inspired by this position from a game I played.</p>
  <pre><code>[FEN &quot;r1b2rk1/p2p1p1p/2qb1PpQ/2p1p3/2p1P3/5N2/PPnP2PP/R1B2RK1 b - - 0 1&quot;]
  </code></pre>
  <p>Black has almost all their pieces, is not in check, and can make 27 (by my count) moves. None of them can prevent mate next turn.</p>
  <p>Let's take this further. What legal position has the most possible moves yet results in being mated next move?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-10-15T22:55:39.987Z
Comments.Text: I've blundered this mate pattern. I noticed computers will sometimes preemptively move the rook
Comments.UserDisplayName: qwr
Tags: <problems><records>
Title: What position has the most possible moves that all lead to being checkmated?
ThreadText: # What position has the most possible moves that all lead to being checkmated?
  
  (Asked by: username_0 on 2023-10-12)
  
  Inspired by this position from a game I played.
  [FEN "r1b2rk1/p2p1p1p/2qb1PpQ/2p1p3/2p1P3/5N2/PPnP2PP/R1B2RK1 b - - 0 1"]
  
  Black has almost all their pieces, is not in check, and can make 27 (by my count) moves. None of them can prevent mate next turn.
  Let's take this further. What legal position has the most possible moves yet results in being mated next move?
  
  **Tags:** problems, records
  
  > **Comments:**
  > **username_1**: I've blundered this mate pattern. I noticed computers will sometimes preemptively move the rook  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2023-10-14. Score: 3 | Accepted answer
  
  I bid 200 moves, with two moves added courtesy of an improvement by @username_3.
  R4Q2/2Q4Q/4Q3/1Q4QB/3Q3b/Q4R1q/2Q1rprN/2nbBKNk w - - 0 1
  
  > **Comments:**
  > **username_3**: Very nice!! How about replacing the black pawn on g3 by a black bishop on h4, and then adding a white bishop on h5? I think that gains a couple!  
  > **username_2**: @JamesMartin Indeed it gains one, thanks. Just shy of 200...  
  > **username_3**: Presumably I'm overlooking something obvious, but why doesn't it gain 2? Newly possible: Be8, Bf7, Bg6, Bg4, Qxg2+, Rxh3. No longer possible: Qgh5, Qhh5, Qhh4, Qhxh3.  
  > **username_2**: @JamesMartin You’re right, I miscounted. Needed a fresh look, it seems.  
  > **username_4**: What's White's checkmate after 1...Qxf3?  
  > **username_2**: @username_4 White is the one *getting* checkmated by Black, not the other way around.  
  > **username_4**: Thanks. What's Black's checkmate after 1. Rxh3?  
  > **username_2**: @username_4 fxe1=Q#/R#.  
  > **username_4**: Thanks, was only looking at Rxg1# for some reason.  
  
  ---
  
  ### Answer by username_5 on 2023-10-15. Score: 2
  
  I only write this as an answer (it isn't) as this is an invaluable source for one-move records, with citations (surely more questions on CSE apply). Since the positions are rather old some records might be broken (or will be broken by Rewan after he fought through the linked site's Excel table).
  
  [Sorry, German only](http://www.skcaissa.de/einzueger.htm)
  
  According to the table (if I interpret the terminology correctly) this would be "erzwungene Mattduldungen". You can search this simply in the SCHWALBE PDB by entering this term as STIP= search. Since even "voluntary" instead of "forced" gives only a record of 201 (P1179075) under this side condition ("With promoted material, legal" - seven subtypes are listed), I guess Rewan's record stands. Allowing illegal positions, 255 (P0005619). Forbidding promoted pieces, 135 (P1178928). Since this peculiar record is missing, I suggest Rewan updates the PDB.
  
  (off to alert MatPlusForum)
  
  
  ---
  
  