Answers.Body: <p>A good reference for this task is Dmitri Baibikov's <em>Length records in 'Last single moves?' problems.</em> Baibikov classifies such problems into types, of which the ones pertinent here are:</p>
  <ul>
  <li>Type A: neither king is in check; the problem does not stipulate the turn player</li>
  <li>Type B: neither king is in check; the problem stipulates the turn player</li>
  <li>Type C: the turn player is in check</li>
  </ul>
  <p>His records for the respective types are:</p>
  <p>Type A: Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991. PDB P0000228.</p>
  <p>What were the last 96 single-moves?</p>
  <pre><code>[Title &quot;Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991. PDB P0000228.&quot;]
  [StartFlipped &quot;0&quot;]
  [fen &quot;KB6/QpN1p2p/r1pkP3/Rqp1p3/bRP5/brP5/pPP5/NB6 w - - 0 1&quot;]
  </code></pre>
  <p>Type B: Andrei Kornilov, Shakhmatnaya Kompozitsia No. 38, 2000, 171 (v). Prize; <em>Length records in 'Last single moves?' problems</em>, Sep 2008, B25. PDB P1300399.</p>
  <pre><code>[Title &quot;Andrei Kornilov, Shakhmatnaya Kompozitsia No. 38, 2000, 171 (v). Prize; *Length records in 'Last single moves?' problems*, Sep 2008, B25. PDB P1300399.&quot;]
  [StartFlipped &quot;0&quot;]
  [fen &quot;2kq1BNr/ppP1PQrB/2ppKPPn/4ppRP/6pp/1P6/8/8 w - - 0 1&quot;]
  </code></pre>
  <p>Type C: Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991 (v). PDB P1300402.</p>
  <pre><code>[Title &quot;Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991 (v). PDB P1300402.&quot;]
  [StartFlipped &quot;0&quot;]
  [fen &quot;KB6/qpN1p2p/r1pkP3/R1p1p3/bRP5/brP5/pPP5/NB6 w - - 0 1&quot;]
  </code></pre>
  
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Answers.Body: <p>As of July 2024, I believe <strong>109</strong> single moves is the record.</p>
  <p>[Note that the terminology used in the retro community is &quot;single moves&quot; rather than &quot;halfmoves&quot;, so I've stuck with that. But it's the same thing: &quot;ply&quot;.]</p>
  <p><a href="https://www.thbrand.de/downloads/lengths-aug-22_v2.pdf" rel="nofollow noreferrer">This document at Thomas Brand's site</a> gives general length records for retractions up to Aug-2022, and I doubt there are significant improvements since then. Authored by Dmitrij Baibikov, Alain Brobecker &amp; Thierry Le Gleuher, it has evolved over 15 years of work.</p>
  <p>According to them, the current records for last moves are:</p>
  <div class="s-table-container"><table class="s-table">
  <thead>
  <tr>
  <th style="text-align: center;">Type</th>
  <th style="text-align: center;">What is this?</th>
  <th style="text-align: center;">Record Single Moves</th>
  <th style="text-align: center;">Author</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: center;">Type A</td>
  <td style="text-align: center;">not told whose move; no check</td>
  <td style="text-align: center;">107</td>
  <td style="text-align: center;">Le Gleuher</td>
  </tr>
  <tr>
  <td style="text-align: center;">Type B</td>
  <td style="text-align: center;">told whose move</td>
  <td style="text-align: center;">108</td>
  <td style="text-align: center;">Le Gleuher</td>
  </tr>
  <tr>
  <td style="text-align: center;">Type C</td>
  <td style="text-align: center;">check</td>
  <td style="text-align: center;">109</td>
  <td style="text-align: center;">Le Gleuher</td>
  </tr>
  <tr>
  <td style="text-align: center;">Type D</td>
  <td style="text-align: center;">duplex</td>
  <td style="text-align: center;">102/103 = 102</td>
  <td style="text-align: center;">Le Gleuher</td>
  </tr>
  <tr>
  <td style="text-align: center;">Type E</td>
  <td style="text-align: center;">colour the pieces; no obvious check</td>
  <td style="text-align: center;">22</td>
  <td style="text-align: center;">Baibikov</td>
  </tr>
  <tr>
  <td style="text-align: center;">Type F</td>
  <td style="text-align: center;">colour the pieces; obvious check</td>
  <td style="text-align: center;">27</td>
  <td style="text-align: center;">Baibikov</td>
  </tr>
  </tbody>
  </table></div>
  <p>You can check out the paper for yourself and see the current length records for each feasible number of pieces, together with detailed solutions. In this post, I just show:</p>
  <p>(1) the overall record - not surprisingly it’s Type C.</p>
  <p>(2) a detailed solution by Henrik Juel for the Type D record.</p>
  <pre><code>[Title &quot;Type C: Last 109 single moves? - Thierry Le Gleuher C p.481 Die Schwalbe 291, 06/2018&quot;]
  [FEN &quot;8/8/6P1/2p5/1P1PPk2/1pPPprp1/BPrqbRPB/NbbR1rKN w - - 0 1&quot;]
  </code></pre>
  <pre><code></code></pre>
  <pre><code>[Title &quot;Type D: Last 102 single moves? Duplex - Thierry Le Gleuher R546 The Problemist 27-6, p. 229, 11/2019&quot;]
  [FEN &quot;8/6p1/8/5PP1/1P3pRP/1p1PPrrr/n2pRrPR/1BNKbk1r w - - 0 1&quot;]
  </code></pre>
  <p>Comment adapted from Henrik Juel who wrote:</p>
  <blockquote>
  <p>Here is the solution from the May 2020 issue of The Problemist from <a href="http://www.theproblemist.org" rel="nofollow noreferrer">www.theproblemist.org</a>, a treasure-trove of info.</p>
  </blockquote>
  <blockquote>
  <p><strong>Retroanalysis</strong>: The wPs captured
  the 4 missing black units. Thus, wPb4 comes from b2, and (Pa2)
  promoted to the extra wR on a8 with (Pa7) letting it pass by switching
  to the b file (first capture of the 3 missing white units). (Pb7) must
  have promoted to a rook on a1 or c1 (second capture). (Ph7) must have
  moved onto the g file (third and final capture) in order to be
  captured. Thus (Pc7) and (Pe7) promoted to rooks on the c and e files,
  respectively. It is not possible to immediately take back a4xb3 or
  c2xd3. The retro-move e4xf5 is forbidden since then the bP which
  promoted on e1 cannot retract to e5. Black can only move in the
  southeast cage, while White’s bishop is free to oscillate between c2
  and b1.</p>
  <p><strong>Black to move: retro</strong> 1.Bc2-b1 Kg1-f1 2.Bb1-c2 Rf1-f2 3.Bc2-b1 Rf2-f3
  4.Bb1-c2 Rf3-g3 5.Bc2-b1 Rg3-h3 6.Rh3-h2 Rh2-h1 7.Bb1-c2 Kh1-g1 8.Bc2-b1 Rg1-f1 9.Bb1-c2 Rf1-f2 10.Bc2-b1 Rf2-f3 11.Bb1-c2 Rf3-g3 12.Rg3-h3 Rh3-h2
  13.Bc2-b1 Kh2-h1 14.Bb1-c2 Rh1-g1 15.Bc2-b1 Kg1-h2 16.Bb1-c2 Rh2-h1
  17.Bc2-b1 Kh1-g1 18.Bb1-c2 Rg1-f1 19.Bc2-b1 Rf1-f2 20.Bb1-c2 Rf2-f3
  21.Rf3-g3 Rg3-h3 22.Bc2-b1 Rh3-h2 23.Bb1-c2 Kh2-h1 24.Bc2-b1 Rh1-g1
  25.Bb1-c2 Kg1-h2 26.Bc2-b1 Rh2-h1 27.Bb1-c2 Kh1-g1 28.Bc2-b1 Rg1-f1
  29.Bb1-c2 Rf1-f2 30.Rf2-f3 Rf3-g3 31.Bc2-b1 Rg3-h3 32.Bb1-c2 Rh3-h2
  33.Bc2-b1 Kh2-h1 34.Bb1-c2 Rh1-g1 35.Bc2-b1 Rg1-f1 36.Rf1-f2 Bf2-e1
  37.Re1-f1 Rf1-g1 38.Bb1-c2 Rg1-h1 39.Bc2-b1 Kh1-h2 40.Bb1-c2 Rh2-h3
  41.Bc2-b1 Rh3-g3 42.Bb1-c2 Bg3-f2 43.Bc2-b1 Rf2-f1 44.Bb1-c2 Rf1-g1
  45.Bc2-b1 Kg1-h1 46.Bb1-c2 Rh1-h2 47.Bc2-b1 Kh2-g1 48.Bb1-c2 Rg1-h1
  49.Bc2-b1 Kh1-h2 50.Bb1-c2 Rh2-h3 51.h3-h4 Bh4-g3 52.Bc2-b1 then 52…Rg3-f3 (or 52...Bg3-h4 53.Bb1-c2 Bh4-g3…) 53.Bb1-c2 Rf3-f2
  54.Bc2-b1 Rf2-f1 55.Bb1-c2 Rf1-g1 56.Bc2-b1 Kg1-h1 57.Bb1-c2 Rh1-h2 58.h2-h3 Rh3-g3 59.Bc2-b1 Bg3-h4 60.Bb1-c2 Rh8-h3 etc…
  The diagram position is a draw and the last 103 single moves are
  determined.</p>
  <p><strong>White to move: retro</strong> 1... Kg1-f1 ... 51.h3-h4 Bh4-g3 52.Bc2-b1 then the same... Here, there are 99 single moves between the diagram position and the retro-move h3-h4. Of course, trying to insert another manoeuvre in the solution would lead
  to an overshoot of the 101 single moves, which would be incompatible
  with the 50 moves rule. Here only 102 last single moves are
  determined. So, we have a new record for last single moves
  for ‘D’ type (Duplex) with 25 pieces. (It is also the overall record
  for Duplex.) With black to move, the same diagram is also a record
  with 25 pieces.</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:20:41.970Z
Answers.Text: This task is definitely not a record. I know longer. We just need to find her.
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:44:38.447Z
Answers.Text: I do not know the author. I only have FEN KB6/QpN1p2p/r1pkP3/Rqp1p3/bRP5/brP5/pPP5/NB6
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:51:30.030Z
Answers.Text: @ЭлсиРинген That is pdb.dieschwalbe.de/P0000228
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:52:20.177Z
Answers.Text: Perhaps I will single out this task as a separate question. Because I still haven't figured out how many exact last moves there really are.
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:55:01.023Z
Answers.Text: Good idea. I can search PDB for the applicable answers.
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:56:16.170Z
Answers.Text: 100: https://pdb.dieschwalbe.de/P1339006 101: https://pdb.dieschwalbe.de/P1011800
Answers.UserDisplayName: Rewan Demontay
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T17:59:23.717Z
Answers.Text: Oh, thank you very much. Otherwise, the task is very well-known. And no one indicates the author.
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T18:03:14.137Z
Answers.Text: All these around 100 moves are tethered by 50M rule which I think helps on uniqueness. Means the path mast be tight with no little eddies. However there might be something way longer if we drop 50M rule
Answers.UserDisplayName: Laska
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T18:32:32.457Z
Answers.Text: Without the 50 moves rule, the record is 55 single moves in total. In a superset. https://www.janko.at/Retros/Glossary/LastMove.htm#prec
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-01T18:35:43.807Z
Answers.Text: But I do not know how many records are in the standard set.
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-03T14:33:01.263Z
Answers.Text: The answer is perfect. But most of the records for the 50-move rule. This is one story. Without the 50-move rule, it's a different story. Plus another kit/over-kit again.
Answers.UserDisplayName: Элси Ринген
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-13T21:37:24.333Z
Answers.Text: "However there might be something way longer if we drop 50M rule"
  Exactly the opposite.
  For example, in a problem of type D without the rule of 50M unique moves, instead of 102 there will be exactly 0.
  1. Bc2-b1 Kg1-f1 2. Bb1-c2 Kf1-g1
  And we came back to the starting position.
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Answers.UserDisplayName: Laska
Body: <p>What is the largest integer x such that there exists a position such that:</p>
  <ul>
  <li>That position can occur in a legal chess game</li>
  <li>It is possible to prove at least x halfmoves have been played</li>
  <li>It is possible to determine what the board position was x moves ago.</li>
  <li>It is possible to determine the last x halfmoves played</li>
  </ul>
  <p>Position includes information about side to move, castling rights and en passant rights. By legal, I mean legal under FIDE laws.
  I know x=20 is <a href="https://puzzling.stackexchange.com/questions/126992/can-you-find-the-last-20-moves">possible</a>.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-01T17:16:16.547Z
Comments.Text: The question is interesting. But even the question is "The maximum number of accurate last single moves?" It can be divided into 4 parts:
  a) without the 50-move rule (standard set of pieces);
  b) without the 50-move rule (overset);
  c) with the 50-move rule (standard);
  d) with the rule of 50 moves (overset).
Comments.UserDisplayName: Элси Ринген
Tags: <retrograde-analysis>
Title: Position where last x halfmoves are determined
ThreadText: # Position where last x halfmoves are determined
  
  (Asked by: username_0 on 2024-07-01)
  
  What is the largest integer x such that there exists a position such that:
  
  * That position can occur in a legal chess game
  * It is possible to prove at least x halfmoves have been played
  * It is possible to determine what the board position was x moves ago.
  * It is possible to determine the last x halfmoves played
  
  Position includes information about side to move, castling rights and en passant rights. By legal, I mean legal under FIDE laws.
  I know x=20 is [possible](https://puzzling.stackexchange.com/questions/126992/can-you-find-the-last-20-moves).
  
  **Tags:** retrograde-analysis
  
  > **Comments:**
  > **username_1**: The question is interesting. But even the question is "The maximum number of accurate last single moves?" It can be divided into 4 parts: a) without the 50-move rule (standard set of pieces); b) without the 50-move rule (overset); c) with the 50-move rule (standard); d) with the rule of 50 moves (overset).  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_3 on 2024-07-01. Score: 6 | Accepted answer
  
  As of July 2024, I believe 109 single moves is the record.
  [Note that the terminology used in the retro community is "single moves" rather than "halfmoves", so I've stuck with that. But it's the same thing: "ply".]
  This document at Thomas Brand's site gives general length records for retractions up to Aug-2022, and I doubt there are significant improvements since then. Authored by Dmitrij Baibikov, Alain Brobecker & Thierry Le Gleuher, it has evolved over 15 years of work.
  According to them, the current records for last moves are:
  
  
  
  Type
  What is this?
  Record Single Moves
  Author
  
  
  
  
  Type A
  not told whose move; no check
  107
  Le Gleuher
  
  
  Type B
  told whose move
  108
  Le Gleuher
  
  
  Type C
  check
  109
  Le Gleuher
  
  
  Type D
  duplex
  102/103 = 102
  Le Gleuher
  
  
  Type E
  colour the pieces; no obvious check
  22
  Baibikov
  
  
  Type F
  colour the pieces; obvious check
  27
  Baibikov
  
  
  
  You can check out the paper for yourself and see the current length records for each feasible number of pieces, together with detailed solutions. In this post, I just show:
  (1) the overall record - not surprisingly it’s Type C.
  (2) a detailed solution by Henrik Juel for the Type D record.
  [Title "Type C: Last 109 single moves? - Thierry Le Gleuher C p.481 Die Schwalbe 291, 06/2018"]
  [FEN "8/8/6P1/2p5/1P1PPk2/1pPPprp1/BPrqbRPB/NbbR1rKN w - - 0 1"]
  
  
  [Title "Type D: Last 102 single moves? Duplex - Thierry Le Gleuher R546 The Problemist 27-6, p. 229, 11/2019"]
  [FEN "8/6p1/8/5PP1/1P3pRP/1p1PPrrr/n2pRrPR/1BNKbk1r w - - 0 1"]
  
  Comment adapted from Henrik Juel who wrote:
  
  Here is the solution from the May 2020 issue of The Problemist from www.theproblemist.org, a treasure-trove of info.
  
  
  Retroanalysis: The wPs captured
  the 4 missing black units. Thus, wPb4 comes from b2, and (Pa2)
  promoted to the extra wR on a8 with (Pa7) letting it pass by switching
  to the b file (first capture of the 3 missing white units). (Pb7) must
  have promoted to a rook on a1 or c1 (second capture). (Ph7) must have
  moved onto the g file (third and final capture) in order to be
  captured. Thus (Pc7) and (Pe7) promoted to rooks on the c and e files,
  respectively. It is not possible to immediately take back a4xb3 or
  c2xd3. The retro-move e4xf5 is forbidden since then the bP which
  promoted on e1 cannot retract to e5. Black can only move in the
  southeast cage, while White’s bishop is free to oscillate between c2
  and b1.
  Black to move: retro 1.Bc2-b1 Kg1-f1 2.Bb1-c2 Rf1-f2 3.Bc2-b1 Rf2-f3
  4.Bb1-c2 Rf3-g3 5.Bc2-b1 Rg3-h3 6.Rh3-h2 Rh2-h1 7.Bb1-c2 Kh1-g1 8.Bc2-b1 Rg1-f1 9.Bb1-c2 Rf1-f2 10.Bc2-b1 Rf2-f3 11.Bb1-c2 Rf3-g3 12.Rg3-h3 Rh3-h2
  13.Bc2-b1 Kh2-h1 14.Bb1-c2 Rh1-g1 15.Bc2-b1 Kg1-h2 16.Bb1-c2 Rh2-h1
  17.Bc2-b1 Kh1-g1 18.Bb1-c2 Rg1-f1 19.Bc2-b1 Rf1-f2 20.Bb1-c2 Rf2-f3
  21.Rf3-g3 Rg3-h3 22.Bc2-b1 Rh3-h2 23.Bb1-c2 Kh2-h1 24.Bc2-b1 Rh1-g1
  25.Bb1-c2 Kg1-h2 26.Bc2-b1 Rh2-h1 27.Bb1-c2 Kh1-g1 28.Bc2-b1 Rg1-f1
  29.Bb1-c2 Rf1-f2 30.Rf2-f3 Rf3-g3 31.Bc2-b1 Rg3-h3 32.Bb1-c2 Rh3-h2
  33.Bc2-b1 Kh2-h1 34.Bb1-c2 Rh1-g1 35.Bc2-b1 Rg1-f1 36.Rf1-f2 Bf2-e1
  37.Re1-f1 Rf1-g1 38.Bb1-c2 Rg1-h1 39.Bc2-b1 Kh1-h2 40.Bb1-c2 Rh2-h3
  41.Bc2-b1 Rh3-g3 42.Bb1-c2 Bg3-f2 43.Bc2-b1 Rf2-f1 44.Bb1-c2 Rf1-g1
  45.Bc2-b1 Kg1-h1 46.Bb1-c2 Rh1-h2 47.Bc2-b1 Kh2-g1 48.Bb1-c2 Rg1-h1
  49.Bc2-b1 Kh1-h2 50.Bb1-c2 Rh2-h3 51.h3-h4 Bh4-g3 52.Bc2-b1 then 52…Rg3-f3 (or 52...Bg3-h4 53.Bb1-c2 Bh4-g3…) 53.Bb1-c2 Rf3-f2
  54.Bc2-b1 Rf2-f1 55.Bb1-c2 Rf1-g1 56.Bc2-b1 Kg1-h1 57.Bb1-c2 Rh1-h2 58.h2-h3 Rh3-g3 59.Bc2-b1 Bg3-h4 60.Bb1-c2 Rh8-h3 etc…
  The diagram position is a draw and the last 103 single moves are
  determined.
  White to move: retro 1... Kg1-f1 ... 51.h3-h4 Bh4-g3 52.Bc2-b1 then the same... Here, there are 99 single moves between the diagram position and the retro-move h3-h4. Of course, trying to insert another manoeuvre in the solution would lead
  to an overshoot of the 101 single moves, which would be incompatible
  with the 50 moves rule. Here only 102 last single moves are
  determined. So, we have a new record for last single moves
  for ‘D’ type (Duplex) with 25 pieces. (It is also the overall record
  for Duplex.) With black to move, the same diagram is also a record
  with 25 pieces.
  
  > **Comments:**
  > **username_1**: This task is definitely not a record. I know longer. We just need to find her.  
  > **username_1**: I do not know the author. I only have FEN KB6/QpN1p2p/r1pkP3/Rqp1p3/bRP5/brP5/pPP5/NB6  
  > **username_4**: @ЭлсиРинген That is pdb.dieschwalbe.de/P0000228  
  > **username_1**: Perhaps I will single out this task as a separate question. Because I still haven't figured out how many exact last moves there really are.  
  > **username_4**: Good idea. I can search PDB for the applicable answers.  
  > **username_4**: 100: https://pdb.dieschwalbe.de/P1339006 101: https://pdb.dieschwalbe.de/P1011800  
  > **username_1**: Oh, thank you very much. Otherwise, the task is very well-known. And no one indicates the author.  
  > **username_3**: All these around 100 moves are tethered by 50M rule which I think helps on uniqueness. Means the path mast be tight with no little eddies. However there might be something way longer if we drop 50M rule  
  > **username_1**: Without the 50 moves rule, the record is 55 single moves in total. In a superset. https://www.janko.at/Retros/Glossary/LastMove.htm#prec  
  > **username_1**: But I do not know how many records are in the standard set.  
  > **username_1**: The answer is perfect. But most of the records for the 50-move rule. This is one story. Without the 50-move rule, it's a different story. Plus another kit/over-kit again.  
  > **username_1**: "However there might be something way longer if we drop 50M rule" Exactly the opposite. For example, in a problem of type D without the rule of 50M unique moves, instead of 102 there will be exactly 0. 1. Bc2-b1 Kg1-f1 2. Bb1-c2 Kf1-g1 And we came back to the starting position.  
  
  ---
  
  ### Answer by username_2 on 2024-07-02. Score: 3
  
  A good reference for this task is Dmitri Baibikov's Length records in 'Last single moves?' problems. Baibikov classifies such problems into types, of which the ones pertinent here are:
  
  Type A: neither king is in check; the problem does not stipulate the turn player
  Type B: neither king is in check; the problem stipulates the turn player
  Type C: the turn player is in check
  
  His records for the respective types are:
  Type A: Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991. PDB P0000228.
  What were the last 96 single-moves?
  [Title "Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991. PDB P0000228."]
  [StartFlipped "0"]
  [fen "KB6/QpN1p2p/r1pkP3/Rqp1p3/bRP5/brP5/pPP5/NB6 w - - 0 1"]
  
  Type B: Andrei Kornilov, Shakhmatnaya Kompozitsia No. 38, 2000, 171 (v). Prize; Length records in 'Last single moves?' problems, Sep 2008, B25. PDB P1300399.
  [Title "Andrei Kornilov, Shakhmatnaya Kompozitsia No. 38, 2000, 171 (v). Prize; *Length records in 'Last single moves?' problems*, Sep 2008, B25. PDB P1300399."]
  [StartFlipped "0"]
  [fen "2kq1BNr/ppP1PQrB/2ppKPPn/4ppRP/6pp/1P6/8/8 w - - 0 1"]
  
  Type C: Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991 (v). PDB P1300402.
  [Title "Gyula Breyer, Chess Amateur, 1922; FIDE Album, 1914-1944; correction: Gerd Wilts, Die Schwalbe, No. 7373, June 1991 (v). PDB P1300402."]
  [StartFlipped "0"]
  [fen "KB6/qpN1p2p/r1pkP3/R1p1p3/bRP5/brP5/pPP5/NB6 w - - 0 1"]
  
  
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