Answers.Body: <p>Yeah they did. And as RemcoGerlich points out, it was probably overlooked due to its rarity.</p>
  <p>However, these are a few interesting points to note:</p>
  <ol>
  <li><p>Long algebraic notation does away with disambiguation since you need to record the origin square of a piece as well. According to <a href="https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Long_algebraic_notation" rel="nofollow noreferrer">Wikipedia</a>, both short and long algebraic notation are acceptable for keeping a record of the moves on a scoresheet, as is required in FIDE rated games. Though, I couldn't cross-verify this from the FIDE rule book.</p>
  </li>
  <li><p>PGN seems to have a proper procedure for double disambiguation. (<a href="https://ia902908.us.archive.org/26/items/pgn-standard-1994-03-12/PGN_standard_1994-03-12.txt" rel="nofollow noreferrer">source</a>)</p>
  </li>
  </ol>
  <blockquote>
  <p>8.2.3.4: Disambiguation<br />
  In the case of ambiguities (multiple pieces of the same type moving to the same square), the first appropriate disambiguating step of the three following steps is taken:<br />
  First, if the moving pieces can be distinguished by their originating files,
  the originating file letter of the moving piece is inserted immediately after
  the moving piece letter.<br />
  Second (when the first step fails), if the moving pieces can be distinguished
  by their originating ranks, the originating rank digit of the moving piece is
  inserted immediately after the moving piece letter.<br />
  Third (when both the first and the second steps fail), the two character square coordinate of the originating square of the moving piece is inserted
  immediately after the moving piece letter.</p>
  </blockquote>
  <ol start="3">
  <li><p>Triple or more disambiguation is not possible. Even if you got 9 queens pointing at one square, recording the rank and file of the desired queen is enough for disambiguation.</p>
  </li>
  <li><p>It doesn't matter how you notate the double disambiguation in the scoresheet if the game is complete (<code>Article 5</code> defines completion of a game). Reason being, you will still be complying with <code>Article 8, clause 1</code> since <code>Appendix C</code> doesn't clarify double disambiguation.</p>
  </li>
  </ol>
  <blockquote>
  <p>In the course of play each player is required to record his own moves
  and those of his opponent in the correct manner, move after move, as
  clearly and legibily as possible, in the algebraic notation (See
  Appendix C), on the scoresheet prescribed for the competition.</p>
  </blockquote>
  <ol start="5">
  <li><p>Due to point 4, you and your opponent could use very different notations for the double disambiguation and get away with it.</p>
  </li>
  <li><p>Interesting situation could arise if the game needs to be adjourned and your last move was double disambiguation. You could technically lose if didn't disambiguate properly since guidelines say the following.</p>
  </li>
  </ol>
  <blockquote>
  <p>If a game is not finished at the end of the time prescribed for play, the arbiter shall require the player having the move to ‘seal’ that move. The player must write his move in unambiguous notation on his scoresheet, put his scoresheet and that of his opponent in an envelope, seal the envelope and only then stop his clock without starting his opponent's clock.</p>
  </blockquote>
  <p>  Note how the term <strong>unambiguous notation</strong> is used instead of <strong>algebraic notation</strong>.</p>
  <p>  Also, if you don't follow this, you lose.</p>
  <blockquote>
  <p>Except in the cases mentioned in the Articles 5, 6.9 and 9.6, the game is lost by a player whose recording of his sealed move:<br />
  a. is ambiguous, or<br />
  b. is recorded such that its true significance is impossible to establish, or<br />
  c. is illegal.</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-24T19:07:24.670Z
Answers.LastActivityDate: 2024-07-24T19:07:24.670Z
Answers.UserDisplayName: Rishav Raj
Body: <p>When I was reading the Laws of Chess, I saw that there was a problem because, in Appendix C-10, it only talked about simple disambiguation. What about double disambiguation?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-20T20:02:19.137Z
Comments.Text: Yes, it seems it only talks about disambiguating two pieces, not three. Who knows whether they forgot or it was deemed too rare to include.
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-20T20:41:27.390Z
Comments.Text: There can be more than three figures. Four. And even eight. Q a1,a2,a3,b1,b3,c1,c2,c3. The move of any queen on b2 can only be written in full notation: Qa1-b2, for example.
Comments.UserDisplayName: Элси Ринген
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-21T07:47:20.327Z
Comments.Text: I even made a chess problem (sort of) about that omission, and yes, I doubt this even wil happen (3Q or N are needed; and if it ever happens, any halfway intelligent player will have the idea to notate full).
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-21T23:30:46.070Z
Comments.Text: @ЭлсиРинген good luck ever getting eight queens in a tournament game though. I think this game holds the record with a 3v2 position: https://www.chessgames.com/perl/chessgame?gid=1667656
Comments.UserDisplayName: David
Tags: <rules><fide><notation>
Title: Did the Laws of Chess forget about double disambiguation?
ThreadText: # Did the Laws of Chess forget about double disambiguation?
  
  (Asked by: username_0 on 2024-07-20)
  
  When I was reading the Laws of Chess, I saw that there was a problem because, in Appendix C-10, it only talked about simple disambiguation. What about double disambiguation?
  
  **Tags:** rules, fide, notation
  
  > **Comments:**
  > **username_1**: Yes, it seems it only talks about disambiguating two pieces, not three. Who knows whether they forgot or it was deemed too rare to include.  
  > **username_2**: There can be more than three figures. Four. And even eight. Q a1,a2,a3,b1,b3,c1,c2,c3. The move of any queen on b2 can only be written in full notation: Qa1-b2, for example.  
  > **username_3**: I even made a chess problem (sort of) about that omission, and yes, I doubt this even wil happen (3Q or N are needed; and if it ever happens, any halfway intelligent player will have the idea to notate full).  
  > **username_4**: @username_2 good luck ever getting eight queens in a tournament game though. I think this game holds the record with a 3v2 position: https://www.chessgames.com/perl/chessgame?gid=1667656  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_5 on 2024-07-24. Score: 1
  
  Yeah they did. And as username_1 points out, it was probably overlooked due to its rarity.
  
  However, these are a few interesting points to note:
  
  1. Long algebraic notation does away with disambiguation since you need to record the origin square of a piece as well. According to [Wikipedia](https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Long_algebraic_notation), both short and long algebraic notation are acceptable for keeping a record of the moves on a scoresheet, as is required in FIDE rated games. Though, I couldn't cross-verify this from the FIDE rule book.
  2. PGN seems to have a proper procedure for double disambiguation. ([source](https://ia902908.us.archive.org/26/items/pgn-standard-1994-03-12/PGN_standard_1994-03-12.txt))
  
  > 8.2.3.4: Disambiguation  
  > In the case of ambiguities (multiple pieces of the same type moving to the same square), the first appropriate disambiguating step of the three following steps is taken:  
  > First, if the moving pieces can be distinguished by their originating files,
  > the originating file letter of the moving piece is inserted immediately after
  > the moving piece letter.  
  > Second (when the first step fails), if the moving pieces can be distinguished
  > by their originating ranks, the originating rank digit of the moving piece is
  > inserted immediately after the moving piece letter.  
  > Third (when both the first and the second steps fail), the two character square coordinate of the originating square of the moving piece is inserted
  > immediately after the moving piece letter.
  
  3. Triple or more disambiguation is not possible. Even if you got 9 queens pointing at one square, recording the rank and file of the desired queen is enough for disambiguation.
  4. It doesn't matter how you notate the double disambiguation in the scoresheet if the game is complete (`Article 5` defines completion of a game). Reason being, you will still be complying with `Article 8, clause 1` since `Appendix C` doesn't clarify double disambiguation.
  
  > In the course of play each player is required to record his own moves
  > and those of his opponent in the correct manner, move after move, as
  > clearly and legibily as possible, in the algebraic notation (See
  > Appendix C), on the scoresheet prescribed for the competition.
  
  5. Due to point 4, you and your opponent could use very different notations for the double disambiguation and get away with it.
  6. Interesting situation could arise if the game needs to be adjourned and your last move was double disambiguation. You could technically lose if didn't disambiguate properly since guidelines say the following.
  
  > If a game is not finished at the end of the time prescribed for play, the arbiter shall require the player having the move to ‘seal’ that move. The player must write his move in unambiguous notation on his scoresheet, put his scoresheet and that of his opponent in an envelope, seal the envelope and only then stop his clock without starting his opponent's clock.
  
    Note how the term **unambiguous notation** is used instead of **algebraic notation**.
  
    Also, if you don't follow this, you lose.
  
  > Except in the cases mentioned in the Articles 5, 6.9 and 9.6, the game is lost by a player whose recording of his sealed move:  
  > a. is ambiguous, or  
  > b. is recorded such that its true significance is impossible to establish, or  
  > c. is illegal.
  
  
  ---
  
  