Answers.Body: <p>9.Qxd8 followed by 10.Nxc6 wins you another pawn. Meanwhile, 9.0-0 gives Black time to protect the c6-pawn.</p>
  
  <p>Given this, 9.Nxc6 is almost as good as 9.Qxd8 for the same reason (winning a pawn). However, 9.Qxd8 is slightly preferable since Black's bishop is out of play on d8 when it recaptures via 9...Bxd8 (if Black recaptures with 9...Rxd8 then 10.Nxc6 exchanges the bishop off with a fork).</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T21:13:14.323Z
Answers.Text: Hmm, I'd have played Qxd8 simply because the side that's up material loves trades.
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-12T01:11:04.280Z
Answers.Text: @Allure Yes, that's a valid reason as well.
Answers.UserDisplayName: Inertial Ignorance
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Answers.LastActivityDate: 2019-05-11T18:14:44.687Z
Answers.UserDisplayName: Inertial Ignorance
Answers.Body: <p>As already pointed out by user1583209, 9.Qxd8 Rxd8 10.Nxc6 followed by Nxe7+ wins an extra pawn. However I wouldn't say that trading your knight Black's dark-squared bishop is good for you because of the strength of the bishop (your knight is also a great piece).</p>
  
  <p>The reason why this continuation is so powerful is, apart from the material advantage, simplification. You remove both queens and a pair of minor pieces from the board, which reduces risk and allows your advantage to be more notorious in the endgame.</p>
  
  <p>Finally, I would strongly suggest you against computer-assisted analysis if you want to sharpen your chess skills. Try to review the game by yourself instead</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:19:12.373Z
Answers.Text: Thanks for your answer. So being 2 pawns up can be a good enough reason to trade down and head for an endgame? I usually do this if I'm a whole piece (or equivalent) up, but generally I'll try to keep my stronger pieces such as a queen until I've got a bigger material advantage. I'll bear that in mind in future games.
Answers.UserDisplayName: Baldrick
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:24:27.750Z
Answers.Text: Indeed, with one or two pawns up simplification is even more effective! The reason is that, with equal pieces and a pawn up, your opponent may have plenty of chances to counterattack but still most endgames will be lost. If you are a piece ahead, reaching an endgame is great, but also if there is a wild attack, it is likely to be in your favour (except maybe in a situation where your king may be very unsafe, which is far from the case in the game you've shown)
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:50:59.347Z
Answers.Text: @David I agree that from a practical perspective, trading pieces is often a good idea if you have a material advantage. Still, here it is also objectively better to trade (engines don't care about "risk").  Without calculating concrete lines, I would be mildly scared playing against the bishop pair in this open position, so I'd disagree with the statement that the c6 knight (which soon has to move is as good as the dark squared bishop.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:08:43.887Z
Answers.LastActivityDate: 2019-05-11T12:08:43.887Z
Answers.UserDisplayName: David
Answers.Body: <p>Castling (9. 0-0) is not a very bad move. You still have a very solid advantage after it due to being a pawn up and having the better pawn structure (black's pawns on a7, c7, c6 are weak and vulnerable).</p>
  
  <p>However you had a better move...</p>
  
  <p>The pawn on c6 is hanging and you could have simply taken it. Both 9. Nxc6 or taking the pawn after queen trades (9. Qxd8 Bxd8 10. Rxd8) are good.</p>
  
  <p>Taking the pawn after queen trades is better, because you will also exchange the knight later on for black's dark squared bishop (which is due to the pawn structure, the stronger piece).</p>
  
  <p>For instance an almost forced sequence could be:</p>
  
  <pre><code>[FEN "r1bq1rk1/p1p1bppp/2p2n2/4N3/4P3/2N5/PPP2PPP/R1BQK2R w KQ - 1 9"]
  
  9. Qxd8 Bxd8
  10.Nxc6 Bb7
  11.Nxd8 Rfxd8
  12.f3
  </code></pre>
  
  <p>In the end white is left with two pawns up, a strong pawn structure and the better bishop.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:10:09.933Z
Answers.Text: I'd say 12.Bg5 is stronger than 12.f3, as we protect the e4 pawn, we continue development and avoid any kind of opposite-bishop draw chances
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:17:08.180Z
Answers.Text: Thanks for the answer. Very instructive. Can you explain why, given the black pawn structure, their dark squared bishop is stronger than a knight, and therefore worth an exchange? And also your final comment - I can see the first two points, but why is my bishop better than his in the end state you show above?
Answers.UserDisplayName: Baldrick
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:20:48.053Z
Answers.Text: @David Bg5 looks good as well. To me mostly a question of personal preference.  Keeping the bishop has the advantage that you can attack the black queenside pawns easily.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:25:28.540Z
Answers.Text: @Baldrick  Generally, in open postions bishops are stronger than knights. The dark squared bishop is particularly strong here because white's most relevant pawn (e4) is covering light squares, and the dark squares are relatively weak. That's why it is advantageous to trade the knight for the bishop.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:26:47.007Z
Answers.Text: @Baldrick: Regarding your second question. As above, the white pawns (e4, f3) are limiting the squares available to the light squared bishop.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:28:47.120Z
Answers.Text: @user1583209: Ah, I see. Thanks very much. So.. that's the reason for the final move. You've got rid of the dark squared bishop, so you build a nice light squared pawn chain that is hard to attack / penetrate by the remaining bishop, and covers a lot of squares on the kingside that black might want to attack.
Answers.UserDisplayName: Baldrick
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:30:59.557Z
Answers.Text: @Baldrick: Exactly and white's dark-squared bishop can easily take care of the dark squares...  For instance attacking the pawns on a7, c7 will be quite annoying for black as he'd either have to defend them (binding a rook to defense) or move them to light squares such as a6 and c6, where they'd hinder the movement of the black bishop.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-11T12:32:19.493Z
Answers.Text: @user1583209: Wow. A lot to take in here, I'll have to look over it and give it more thought. It's a tricky old game, this! :)
Answers.UserDisplayName: Baldrick
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Answers.LastActivityDate: 2019-05-11T12:43:23.240Z
Answers.LastEditDate: 2019-05-11T12:43:23.240Z
Answers.UserDisplayName: user1583209
Body: <p>I'm a novice player, trying to improve. In the following game I played as white recently on chess.com, I analysed afterwards and my worst move of the game was apparently when I castled. The engine strongly favoured trading queens on move 9.</p>
  
  <pre><code>[FEN ""]
  
  1. e4 e5 
  2. Nf3 d6 
  3. Nc3 Nf6 
  4. d4 Nc6 
  5. Bb5 Be7 
  6. Bxc6+ bxc6 
  7. dxe5 dxe5 
  8. Nxe5 O-O 
  9. O-O Bg4 
  10. Nxg4 Nxg4 
  11. Qxg4 Bb4 
  12. a3 Bxc3 
  13. bxc3 Rb8 
  14. Be3 a5 
  15. Bd4 Rb4 
  16. Qxg7# 1-0
  </code></pre>
  
  <p>Why is this? I can't quite see why the trade is beneficial, and so much better than castling at this point.</p>
  
  <p>Maybe I'm giving up initiative by allowing black to initiate a trade? Or perhaps I'm better developed, so it makes more sense to trade down and benefit for more activity with my pieces? It was a strong 2 point difference from what seems like a fairly even choice from my perspective.</p>
  
  <p>Any ideas why the castling move at that point was such a bad choice?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T12:04:49.993Z
Comments.Text: Don't use engines for analysis if you want to improve your skills!
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T12:21:51.803Z
Comments.Text: @David: Thanks for the suggestion. I tend to review myself first, then check the engine, then try to find a stronger human player to advise me if I'm confused. Should I stop using the engine altogether? I feel I would miss things I could learn - the engine does reliably point out blunders for example.
Comments.UserDisplayName: Baldrick
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T12:26:17.393Z
Comments.Text: Yes. My advice would be to get rid of the engine comletely, specially if you have the possibility of checking the game wih a human player. The engine will often "find a better move" but it won't tell you the reason why the move is better (if you could understand the reason yourself, then you could also find the move with a litle more effort) Also, some "computer accurate moves" are far from the most practical choice in many positions
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T12:30:44.520Z
Comments.Text: @David: I see the point. I might end up posting a more questions on here. I feel I've learnt a lot. The engine sometimes suggests moves that create a very complex hard-to-defend position. Fine for a engine, that can calculate many different lines at once, and deem them all safe. But for me, it just seems impossible to cover all the angles.
Comments.UserDisplayName: Baldrick
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T12:36:35.923Z
Comments.Text: @David: I'm guessing the engine evaluation in that case was that I potentially missed a chance of a free pawn (or a forcing line that led to one) by giving a tempo to the opponent by castling.
Comments.UserDisplayName: Baldrick
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T16:17:26.553Z
Comments.Text: Engines are a great way to improve your game, if used correctly. Which you are doing. They can help you discover bad habits that would be hard to turn up in discussions with human players. Definitely do both.
Comments.UserDisplayName: Tim Grant
Tags: <engines><analysis><castling><exchange><trading>
Title: Why was castling bad for white in this game, and engine strongly prefered trading queens?
ThreadText: # Why was castling bad for white in this game, and engine strongly prefered trading queens?
  
  (Asked by: username_0 on 2019-05-11)
  
  I'm a novice player, trying to improve. In the following game I played as white recently on chess.com, I analysed afterwards and my worst move of the game was apparently when I castled. The engine strongly favoured trading queens on move 9.
  [FEN ""]
  
  1. e4 e5 
  2. Nf3 d6 
  3. Nc3 Nf6 
  4. d4 Nc6 
  5. Bb5 Be7 
  6. Bxc6+ bxc6 
  7. dxe5 dxe5 
  8. Nxe5 O-O 
  9. O-O Bg4 
  10. Nxg4 Nxg4 
  11. Qxg4 Bb4 
  12. a3 Bxc3 
  13. bxc3 Rb8 
  14. Be3 a5 
  15. Bd4 Rb4 
  16. Qxg7# 1-0
  
  Why is this? I can't quite see why the trade is beneficial, and so much better than castling at this point.
  Maybe I'm giving up initiative by allowing black to initiate a trade? Or perhaps I'm better developed, so it makes more sense to trade down and benefit for more activity with my pieces? It was a strong 2 point difference from what seems like a fairly even choice from my perspective.
  Any ideas why the castling move at that point was such a bad choice?
  
  **Tags:** engines, analysis, castling, exchange, trading
  
  > **Comments:**
  > **username_1**: Don't use engines for analysis if you want to improve your skills!  
  > **username_0**: @username_1: Thanks for the suggestion. I tend to review myself first, then check the engine, then try to find a stronger human player to advise me if I'm confused. Should I stop using the engine altogether? I feel I would miss things I could learn - the engine does reliably point out blunders for example.  
  > **username_1**: Yes. My advice would be to get rid of the engine comletely, specially if you have the possibility of checking the game wih a human player. The engine will often "find a better move" but it won't tell you the reason why the move is better (if you could understand the reason yourself, then you could also find the move with a litle more effort) Also, some "computer accurate moves" are far from the most practical choice in many positions  
  > **username_0**: @username_1: I see the point. I might end up posting a more questions on here. I feel I've learnt a lot. The engine sometimes suggests moves that create a very complex hard-to-defend position. Fine for a engine, that can calculate many different lines at once, and deem them all safe. But for me, it just seems impossible to cover all the angles.  
  > **username_0**: @username_1: I'm guessing the engine evaluation in that case was that I potentially missed a chance of a free pawn (or a forcing line that led to one) by giving a tempo to the opponent by castling.  
  > **username_2**: Engines are a great way to improve your game, if used correctly. Which you are doing. They can help you discover bad habits that would be hard to turn up in discussions with human players. Definitely do both.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_5 on 2019-05-11. Score: 8 | Accepted answer
  
  Castling (9. 0-0) is not a very bad move. You still have a very solid advantage after it due to being a pawn up and having the better pawn structure (black's pawns on a7, c7, c6 are weak and vulnerable).
  However you had a better move...
  The pawn on c6 is hanging and you could have simply taken it. Both 9. Nxc6 or taking the pawn after queen trades (9. Qxd8 Bxd8 10. Rxd8) are good.
  Taking the pawn after queen trades is better, because you will also exchange the knight later on for black's dark squared bishop (which is due to the pawn structure, the stronger piece).
  For instance an almost forced sequence could be:
  [FEN "r1bq1rk1/p1p1bppp/2p2n2/4N3/4P3/2N5/PPP2PPP/R1BQK2R w KQ - 1 9"]
  
  9. Qxd8 Bxd8
  10.Nxc6 Bb7
  11.Nxd8 Rfxd8
  12.f3
  
  In the end white is left with two pawns up, a strong pawn structure and the better bishop.
  
  > **Comments:**
  > **username_1**: I'd say 12.Bg5 is stronger than 12.f3, as we protect the e4 pawn, we continue development and avoid any kind of opposite-bishop draw chances  
  > **username_0**: Thanks for the answer. Very instructive. Can you explain why, given the black pawn structure, their dark squared bishop is stronger than a knight, and therefore worth an exchange? And also your final comment - I can see the first two points, but why is my bishop better than his in the end state you show above?  
  > **username_5**: @username_1 Bg5 looks good as well. To me mostly a question of personal preference.  Keeping the bishop has the advantage that you can attack the black queenside pawns easily.  
  > **username_5**: @username_0  Generally, in open postions bishops are stronger than knights. The dark squared bishop is particularly strong here because white's most relevant pawn (e4) is covering light squares, and the dark squares are relatively weak. That's why it is advantageous to trade the knight for the bishop.  
  > **username_5**: @username_0: Regarding your second question. As above, the white pawns (e4, f3) are limiting the squares available to the light squared bishop.  
  > **username_0**: @username_5: Ah, I see. Thanks very much. So.. that's the reason for the final move. You've got rid of the dark squared bishop, so you build a nice light squared pawn chain that is hard to attack / penetrate by the remaining bishop, and covers a lot of squares on the kingside that black might want to attack.  
  > **username_5**: @username_0: Exactly and white's dark-squared bishop can easily take care of the dark squares...  For instance attacking the pawns on a7, c7 will be quite annoying for black as he'd either have to defend them (binding a rook to defense) or move them to light squares such as a6 and c6, where they'd hinder the movement of the black bishop.  
  > **username_0**: @username_5: Wow. A lot to take in here, I'll have to look over it and give it more thought. It's a tricky old game, this! :)  
  
  ---
  
  ### Answer by username_3 on 2019-05-11. Score: 5
  
  9.Qxd8 followed by 10.Nxc6 wins you another pawn. Meanwhile, 9.0-0 gives Black time to protect the c6-pawn.
  
  Given this, 9.Nxc6 is almost as good as 9.Qxd8 for the same reason (winning a pawn). However, 9.Qxd8 is slightly preferable since Black's bishop is out of play on d8 when it recaptures via 9...Bxd8 (if Black recaptures with 9...Rxd8 then 10.Nxc6 exchanges the bishop off with a fork).
  
  > **Comments:**
  > **username_4**: Hmm, I'd have played Qxd8 simply because the side that's up material loves trades.  
  > **username_3**: @username_4 Yes, that's a valid reason as well.  
  
  ---
  
  ### Answer by username_1 on 2019-05-11. Score: 3
  
  As already pointed out by username_5, 9.Qxd8 Rxd8 10.Nxc6 followed by Nxe7+ wins an extra pawn. However I wouldn't say that trading your knight Black's dark-squared bishop is good for you because of the strength of the bishop (your knight is also a great piece).
  
  The reason why this continuation is so powerful is, apart from the material advantage, simplification. You remove both queens and a pair of minor pieces from the board, which reduces risk and allows your advantage to be more notorious in the endgame.
  
  Finally, I would strongly suggest you against computer-assisted analysis if you want to sharpen your chess skills. Try to review the game by yourself instead
  
  > **Comments:**
  > **username_0**: Thanks for your answer. So being 2 pawns up can be a good enough reason to trade down and head for an endgame? I usually do this if I'm a whole piece (or equivalent) up, but generally I'll try to keep my stronger pieces such as a queen until I've got a bigger material advantage. I'll bear that in mind in future games.  
  > **username_1**: Indeed, with one or two pawns up simplification is even more effective! The reason is that, with equal pieces and a pawn up, your opponent may have plenty of chances to counterattack but still most endgames will be lost. If you are a piece ahead, reaching an endgame is great, but also if there is a wild attack, it is likely to be in your favour (except maybe in a situation where your king may be very unsafe, which is far from the case in the game you've shown)  
  > **username_5**: @username_1 I agree that from a practical perspective, trading pieces is often a good idea if you have a material advantage. Still, here it is also objectively better to trade (engines don't care about "risk").  Without calculating concrete lines, I would be mildly scared playing against the bishop pair in this open position, so I'd disagree with the statement that the c6 knight (which soon has to move is as good as the dark squared bishop.  
  
  ---
  
  