Answers.Body: <p>I'm not very good at proofgames, but if I counted correctly, 12 move suffice:</p>
  <pre><code>[FEN &quot;rnb3nr/pppp1Npp/4p3/8/4k3/1QP2PPB/PPP2PKP/RN5R w KQkq - 0 1&quot;]
  </code></pre>
  <p>Moves are obvious: Black sacrifices <code>B-b4-c3</code> and <code>Q-xBg5-g4-f3</code> in that order, White plays <code>Q-d5-b3</code>. Last moves are <code>10.Nf7+ Ke4 11.Kg2 Qf3+ 12.exf3#</code>. An retro expert will manage 11, at least :-)</p>
  <p>Proof game:</p>
  <pre><code>[FEN &quot;&quot;]
  1.Nf3 e6 2.Ne5 Bb4 3.g3 Bc3 4.dxc3 Ke7 5.Qd5 Kf6 6.Qb3 Kf5 7.Bg5 Qxg5 8.Bh3 Qg4 9.Kf1 Ke4 10.Nxf7 Qh5 {Black has one extra tempo to waste, at this point or before} 11.Kg2 Qf3 12.exf3#
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T12:04:12.813Z
Answers.Text: THX for the PG, I was too idle at the time :-) (But I have been pwned big time anyway...)
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T23:54:08.297Z
Answers.Text: "a retro expert will manage 11, at least" Evargalo: 8 ;)
Answers.UserDisplayName: DialFrost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T06:59:05.660Z
Answers.LastActivityDate: 2022-04-14T13:51:53.077Z
Answers.LastEditDate: 2022-04-14T13:51:53.077Z
Answers.UserDisplayName: Hauke Reddmann
Answers.Body: <p>I think this achieves the task in 15 plies (mate after White's 8th move):</p>
  <pre><code>[FEN &quot;&quot;]
  1. b4 d6 2. a4 Bf5 3. Nf3 Bd3 4. Ba3 Kd7 5. Nc3 Kc6 6. Nd5 Kxd5 7. e4+ Kc4 8. cxd3#
  </code></pre>
  <p>The 9 white units necessary for mate are 5 pawns, 2 bishops, 1 knight and the queen.</p>
  <p>In case you are bothered by the two Bishop+Pawn batteries (one might consider than c5 is attacked twice, by Pb4 and Ba3), then we need one more move:</p>
  <pre><code>[FEN &quot;&quot;]
  1. Nc3 d5 2. Nb5 Kd7 3. e4 Kc6 4. Nxa7+ Kc5 5. Ke2 d4 6. a3 Kc4 7. b4 Nd7 8. Nf3 d3+ 9. cxd3#
  </code></pre>
  <p>Mate is delivered by 5 pawns, 2 knights, 1 king and 1 queen.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T12:07:50.403Z
Answers.Text: This screams for a narrowed-down question: Assume you are a Bohemian Problemist, then pieces (especially officers) idling around on a1 etc. are a no-no. Thus: Proof game to a position where White only has the 9 pieces needed for mating. (Should take at most around 10 more moves with the bQ gobbling them.)
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T13:57:18.100Z
Answers.Text: FWIW I am most definitely not bothered by the bishop+pawn batteries. (I did consider a more restrictive definition that requires there to be no piece from either side touching the king, though).
Answers.UserDisplayName: Steve Bennett
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T19:35:46.140Z
Answers.Text: @SteveBennett No piece from either side touching the king? Doesn't the checkmate have to be delivered by a pawn?
Answers.UserDisplayName: bof
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-15T00:17:07.857Z
Answers.Text: Yeah, good point, thank you.
Answers.UserDisplayName: Steve Bennett
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-15T08:27:44.987Z
Answers.Text: @HaukeReddmann : that's worth creating another question ! (also, are idle Black units allowed ?)
Answers.UserDisplayName: Evargalo
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-15T14:34:34.967Z
Answers.Text: @Evargalo: yes, since otherwise Black would be down to the nude king. Of course you could add a few pinned pieces to speed up the gobbling :-)
Answers.UserDisplayName: Hauke Reddmann
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Answers.CreationDate: 2022-04-14T10:09:07.113Z
Answers.LastActivityDate: 2022-04-15T08:33:18.187Z
Answers.LastEditDate: 2022-04-15T08:33:18.187Z
Answers.UserDisplayName: Evargalo
Body: <p>Define an &quot;elegant&quot; checkmate as one in which</p>
  <ul>
  <li>the king is not on the edge of the board</li>
  <li>the king and each of the 8 squares surrounding it are each attacked by exactly one, different opponent piece. (In other words: 9 pieces each attack exactly one of those squares)</li>
  <li>none of the squares touching the king are occupied by pieces of the king's colour</li>
  </ul>
  <p>For instance, this is an elegant checkmate:</p>
  <pre><code>8/3B1N2/2K5/8/4k3/1N1P2P1/2P2PP1/8 w - - 0 1
  </code></pre>
  <p>Now, what is the shortest game that leads to an elegant checkmate?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-14T06:45:39.647Z
Comments.Text: Might be termed a "Pachman mate", for reasons problemists know (which also have terms for the requirements, but I only know the German terms at the moment). But that's not why I write - d3 is doubly attacked! Replace Sc5 by Pd3!
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-14T13:46:35.403Z
Comments.Text: Thanks, I thought there would probably be a term for it. (And thanks for catching the error.)
Comments.UserDisplayName: Steve Bennett
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-14T23:59:48.473Z
Comments.Text: I keep coming up with good checkmates, but i always have one piece that is guarding 2 squares :(
Comments.UserDisplayName: DialFrost
Tags: <problems><checkmate>
Title: Shortest game to "elegant" mate
ThreadText: # Shortest game to "elegant" mate
  
  (Asked by: username_0 on 2022-04-14)
  
  Define an "elegant" checkmate as one in which
  
  * the king is not on the edge of the board
  * the king and each of the 8 squares surrounding it are each attacked by exactly one, different opponent piece. (In other words: 9 pieces each attack exactly one of those squares)
  * none of the squares touching the king are occupied by pieces of the king's colour
  
  For instance, this is an elegant checkmate:
  
  ```
  8/3B1N2/2K5/8/4k3/1N1P2P1/2P2PP1/8 w - - 0 1
  
  ```
  
  Now, what is the shortest game that leads to an elegant checkmate?
  
  **Tags:** problems, checkmate
  
  > **Comments:**
  > **username_1**: Might be termed a "Pachman mate", for reasons problemists know (which also have terms for the requirements, but I only know the German terms at the moment). But that's not why I write - d3 is doubly attacked! Replace Sc5 by Pd3!  
  > **username_0**: Thanks, I thought there would probably be a term for it. (And thanks for catching the error.)  
  > **username_2**: I keep coming up with good checkmates, but i always have one piece that is guarding 2 squares :(  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2022-04-14. Score: 2
  
  I'm not very good at proofgames, but if I counted correctly, 12 move suffice:
  
  ```
  [FEN "rnb3nr/pppp1Npp/4p3/8/4k3/1QP2PPB/PPP2PKP/RN5R w KQkq - 0 1"]
  
  ```
  
  Moves are obvious: Black sacrifices `B-b4-c3` and `Q-xBg5-g4-f3` in that order, White plays `Q-d5-b3`. Last moves are `10.Nf7+ Ke4 11.Kg2 Qf3+ 12.exf3#`. An retro expert will manage 11, at least :-)
  
  Proof game:
  
  ```
  [FEN ""]
  1.Nf3 e6 2.Ne5 Bb4 3.g3 Bc3 4.dxc3 Ke7 5.Qd5 Kf6 6.Qb3 Kf5 7.Bg5 Qxg5 8.Bh3 Qg4 9.Kf1 Ke4 10.Nxf7 Qh5 {Black has one extra tempo to waste, at this point or before} 11.Kg2 Qf3 12.exf3#
  
  ```
  
  > **Comments:**
  > **username_1**: THX for the PG, I was too idle at the time :-) (But I have been pwned big time anyway...)  
  > **username_2**: "a retro expert will manage 11, at least" username_3: 8 ;)  
  
  ---
  
  ### Answer by username_3 on 2022-04-14. Score: 2
  
  I think this achieves the task in 15 plies (mate after White's 8th move):
  
  ```
  [FEN ""]
  1. b4 d6 2. a4 Bf5 3. Nf3 Bd3 4. Ba3 Kd7 5. Nc3 Kc6 6. Nd5 Kxd5 7. e4+ Kc4 8. cxd3#
  
  ```
  
  The 9 white units necessary for mate are 5 pawns, 2 bishops, 1 knight and the queen.
  
  In case you are bothered by the two Bishop+Pawn batteries (one might consider than c5 is attacked twice, by Pb4 and Ba3), then we need one more move:
  
  ```
  [FEN ""]
  1. Nc3 d5 2. Nb5 Kd7 3. e4 Kc6 4. Nxa7+ Kc5 5. Ke2 d4 6. a3 Kc4 7. b4 Nd7 8. Nf3 d3+ 9. cxd3#
  
  ```
  
  Mate is delivered by 5 pawns, 2 knights, 1 king and 1 queen.
  
  > **Comments:**
  > **username_1**: This screams for a narrowed-down question: Assume you are a Bohemian Problemist, then pieces (especially officers) idling around on a1 etc. are a no-no. Thus: Proof game to a position where White only has the 9 pieces needed for mating. (Should take at most around 10 more moves with the bQ gobbling them.)  
  > **username_0**: FWIW I am most definitely not bothered by the bishop+pawn batteries. (I did consider a more restrictive definition that requires there to be no piece from either side touching the king, though).  
  > **username_4**: @username_0 No piece from either side touching the king? Doesn't the checkmate have to be delivered by a pawn?  
  > **username_0**: Yeah, good point, thank you.  
  > **username_3**: @username_1 : that's worth creating another question ! (also, are idle Black units allowed ?)  
  > **username_1**: @username_3: yes, since otherwise Black would be down to the nude king. Of course you could add a few pinned pieces to speed up the gobbling :-)  
  
  ---
  
  