Answers.Body: <p>I don't know what chess.com's algorithm for deciding on &quot;brilliant&quot; moves is exactly, but your &quot;simple king-side castle&quot; is in fact close to &quot;some insane sacrifice&quot; that gives a small advantage.</p>
  <p>You see, your 4.Ng5 was a blunder that gives a piece away for nothing, black should just take it with 4...Qxg5.</p>
  <p>However, after 4...Nh6 5.0-0, the piece is still en prise, but now 5...Qxg5 doesn't work because of 6.d4! and now white wins the piece back, and has a small advantage because of the bishop pair and the slightly odd positions of the black queen and knight on h6.</p>
  <p>After 4...Qxg5, 5.d4 didn't work because black had 5...Qxg2, attacking the rook, so he can move the bishop to safety after white plays 6.Rf1.</p>
  <p>So your simple king side castle makes your previous blunder actually work, because it covers pawn g2.</p>
  <pre><code>[FEN &quot;&quot;]
  
  1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Ng5?? Nh6?? (4...Qxg5 5.d4? Qxg2 6.Rf1 Nxd4) 5.O-O! Qxg5 6.d4! Qh4 7.dxc5
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-14T09:53:51.220Z
Answers.LastActivityDate: 2023-01-14T09:53:51.220Z
Answers.UserDisplayName: RemcoGerlich
Body: <pre><code>[FEN &quot;&quot;]
  
  1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Ng5 Nh6 5. O-O
  </code></pre>
  <p>Why did chess.com mark this move as a brilliant move? It was quite surprising to see a simple king-side castle getting a <code>(!!) brilliant</code> which — at my level — is usually only seen for some insane sacrifice that gives you a winning advantage. For some context, my elo is in the ballpark of around 900 and I won this match with an 86% accuracy.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-14T09:55:42.697Z
Comments.Text: It was a brilliant move because chess.com thought you planned a well-calculated sacrifice. It thought you were trying to counter `Qxg5` with `d4`. The platform didn't know you simply blundered.
Comments.UserDisplayName: SmallChess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-14T14:20:06.507Z
Comments.Text: Well, that's was my intention all along. See the full game here: https://www.chess.com/game/live/67425177687 (though I will admit I usually go d4 before castling, and hope my opponent doesn't do `Qxg2`)
Comments.UserDisplayName: Shane
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-14T14:26:21.360Z
Comments.Text: Or better -- not notice the delivered attack on the queen at all!
Comments.UserDisplayName: Shane
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-15T10:44:22.010Z
Comments.Text: @Shane see my answer to this question: https://chess.stackexchange.com/questions/41357/would-quadruple-forking-be-considered-a-brilliant-move-according-to-stockfish
Comments.UserDisplayName: David
Tags: <analysis>
Title: Why was this castling move so "brilliant"?
ThreadText: # Why was this castling move so "brilliant"?
  
  (Asked by: username_0 on 2023-01-14)
  
  [FEN ""]
  
  1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Ng5 Nh6 5. O-O
  
  Why did chess.com mark this move as a brilliant move? It was quite surprising to see a simple king-side castle getting a (!!) brilliant which — at my level — is usually only seen for some insane sacrifice that gives you a winning advantage. For some context, my elo is in the ballpark of around 900 and I won this match with an 86% accuracy.
  
  **Tags:** analysis
  
  > **Comments:**
  > **username_1**: It was a brilliant move because chess.com thought you planned a well-calculated sacrifice. It thought you were trying to counter `Qxg5` with `d4`. The platform didn't know you simply blundered.  
  > **username_0**: Well, that's was my intention all along. See the full game here: https://www.chess.com/game/live/67425177687 (though I will admit I usually go d4 before castling, and hope my opponent doesn't do `Qxg2`)  
  > **username_0**: Or better -- not notice the delivered attack on the queen at all!  
  > **username_2**: @username_0 see my answer to this question: https://chess.stackexchange.com/questions/41357/would-quadruple-forking-be-considered-a-brilliant-move-according-to-stockfish  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_3 on 2023-01-14. Score: 6 | Accepted answer
  
  I don't know what chess.com's algorithm for deciding on "brilliant" moves is exactly, but your "simple king-side castle" is in fact close to "some insane sacrifice" that gives a small advantage.
  You see, your 4.Ng5 was a blunder that gives a piece away for nothing, black should just take it with 4...Qxg5.
  However, after 4...Nh6 5.0-0, the piece is still en prise, but now 5...Qxg5 doesn't work because of 6.d4! and now white wins the piece back, and has a small advantage because of the bishop pair and the slightly odd positions of the black queen and knight on h6.
  After 4...Qxg5, 5.d4 didn't work because black had 5...Qxg2, attacking the rook, so he can move the bishop to safety after white plays 6.Rf1.
  So your simple king side castle makes your previous blunder actually work, because it covers pawn g2.
  [FEN ""]
  
  1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Ng5?? Nh6?? (4...Qxg5 5.d4? Qxg2 6.Rf1 Nxd4) 5.O-O! Qxg5 6.d4! Qh4 7.dxc5
  
  
  ---
  
  