Answers.Body: <p>Black's knight is almost trapped - it's got literally nowhere to go after 5. c3. By avoiding the trade, therefore, White forces Black into contortions to avoid losing a piece:</p>
  <ul>
  <li>1...a6 2. a4! leaves the knight as trapped as before</li>
  <li>After 1...f5 White ignores Black's sortie and plays 2. c3, winning the knight</li>
  <li>That leaves 1...c6 as the only move that doesn't lose the piece - but then check out what happens to Black's pieces after 2. c3 Nb5 3. a4 Nc7 (this knight is <em>really</em> sad) 4. Nc4. Black's pieces are underdeveloped, congested, and have no future, giving White a powerful development advantage.</li>
  </ul>
  <p>Stockfish evidently thinks White's dynamic advantage in the last line is worth more than a pawn (most experts would probably agree as well). But, at least for this human, there's nothing wrong with going for the pawn-up position after Nxd4. Black gets the development advantage, but White's position is still not bad, and having extra material is very comforting.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-04-04T02:21:25.980Z
Answers.Text: And there is the human reason too. It is easier to calculate if you can mostly restrict yourself to staying ahead in material while having a reasonable position. Computers can calculate even if there is only one correct move every turn, but humans cannot... Stockfish's evaluation is tailored for Stockfish's capabilities, not human capabilities.
Answers.UserDisplayName: user21820
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-04-03T00:31:51.550Z
Answers.LastActivityDate: 2024-04-03T00:31:51.550Z
Answers.UserDisplayName: Allure
Body: <p>In the Scotch, normally Black takes the d4 pawn. When Black doesn't, White is advised to take up more space in the center and play a slower, closed game, if I understand right.</p>
  <p>In this sequence, Black responds by 4... Nd4. However, the engine's next recommendation surprises me -- rather than 5. Nxd4, the engine prefers 5. Nfd2, which at first glance seems to block in White's dark-squared bishop (in addition to giving up on the free pawn). The preference is pretty strong (2.56 vs 1.77, Stockfish at depth=32). I can't calculate this one out, any ideas?</p>
  <pre><code>[Event &quot;?&quot;]
  [Site &quot;?&quot;]
  [Date &quot;?&quot;]
  [Round &quot;?&quot;]
  [White &quot;?&quot;]
  [Black &quot;?&quot;]
  [Result &quot;?&quot;]
  [Title &quot;?&quot;]
  [FEN &quot;&quot;]
  [StartPly &quot;15&quot;]
  1. e4 e5 2. Nf3 Nc6 3. d4 Bd6 4. d5 Nd4 
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-04-03T00:28:46.630Z
Comments.Text: Is Stockfish's preference for the unintuitive Nfd2? It is hard then to save the BN from c3 and a4.
Comments.UserDisplayName: Philip Roe
Tags: <engines><scotch-game>
Title: An unusual scotch sequence -- why not take a free pawn?
ThreadText: # An unusual scotch sequence -- why not take a free pawn?
  
  (Asked by: username_0 on 2024-04-02)
  
  In the Scotch, normally Black takes the d4 pawn. When Black doesn't, White is advised to take up more space in the center and play a slower, closed game, if I understand right.
  In this sequence, Black responds by 4... Nd4. However, the engine's next recommendation surprises me -- rather than 5. Nxd4, the engine prefers 5. Nfd2, which at first glance seems to block in White's dark-squared bishop (in addition to giving up on the free pawn). The preference is pretty strong (2.56 vs 1.77, Stockfish at depth=32). I can't calculate this one out, any ideas?
  [Event "?"]
  [Site "?"]
  [Date "?"]
  [Round "?"]
  [White "?"]
  [Black "?"]
  [Result "?"]
  [Title "?"]
  [FEN ""]
  [StartPly "15"]
  1. e4 e5 2. Nf3 Nc6 3. d4 Bd6 4. d5 Nd4
  
  **Tags:** engines, scotch-game
  
  > **Comments:**
  > **username_1**: Is Stockfish's preference for the unintuitive Nfd2? It is hard then to save the BN from c3 and a4.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2024-04-03. Score: 14 | Accepted answer
  
  Black's knight is almost trapped - it's got literally nowhere to go after 5. c3. By avoiding the trade, therefore, White forces Black into contortions to avoid losing a piece:
  
  * 1...a6 2. a4! leaves the knight as trapped as before
  * After 1...f5 White ignores Black's sortie and plays 2. c3, winning the knight
  * That leaves 1...c6 as the only move that doesn't lose the piece - but then check out what happens to Black's pieces after 2. c3 Nb5 3. a4 Nc7 (this knight is *really* sad) 4. Nc4. Black's pieces are underdeveloped, congested, and have no future, giving White a powerful development advantage.
  
  Stockfish evidently thinks White's dynamic advantage in the last line is worth more than a pawn (most experts would probably agree as well). But, at least for this human, there's nothing wrong with going for the pawn-up position after Nxd4. Black gets the development advantage, but White's position is still not bad, and having extra material is very comforting.
  
  > **Comments:**
  > **username_3**: And there is the human reason too. It is easier to calculate if you can mostly restrict yourself to staying ahead in material while having a reasonable position. Computers can calculate even if there is only one correct move every turn, but humans cannot... Stockfish's evaluation is tailored for Stockfish's capabilities, not human capabilities.  
  
  ---
  
  