Answers.Body: <p>Often black plays b6/Bb7/c5 to support an attack against the White d-pawn, and at times even Na6 to support c5. Obstructing the c-pawn slows down or prevents these kinds of maneuvers. Nc6 is an awkward placement of the knight on the queenside with d5/e6 being played by black, as it has no real good second move from c6 to get out of the c-pawns way, thus losing time, if black wants to follow up with ...c6 or ...c5. The move ...c5 is a "breaking" move that black wants in many openings, including the Caro-Kann, the French, etc., and not just d-pawn openings. A knight on c6 is generally speaking a 'good' knight when ...e5 and/or ...c5 has been played, i.e., king's pawn openings, The Sicilian Defense, etc.</p>
  
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Answers.CreationDate: 2017-01-03T18:27:50.673Z
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Answers.UserDisplayName: Priyome
Answers.Body: <p>One thing would be it allows you to put more pressure on d4, having both the pawn and knight hitting it instead of the pawn being blocked behind the knight on c7. The king's pawn is usually supporting the queen's pawn on d5.</p>
  
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Answers.CreationDate: 2016-12-30T22:27:03.630Z
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Answers.UserDisplayName: Jerry Snitselaar
Answers.Body: <p>I've often thought that the author over-emphasized this point.  But there are good reasons for ...c5 in Queen's pawn openings.  This single move accomplishes three things.  1. Put pressure on d4, as @Jerry Snitselaar has said.  2. Make room for the Queen Bishop, assuming ...e5 is not workable.  3. Create a meaningful open file for a rook--again, assuming ...e5 cannot reasonably be played.  (I say "meaningful" because it is relatively easy to open <em>some</em> file, such as with the a- or b-pawn, but usually a rook on the c-file hits more valuable targets, and besides, it is usually important to prevent White dominance on this file.)</p>
  
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Answers.CreationDate: 2017-01-02T22:37:03.210Z
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Answers.UserDisplayName: rolando2
Body: <p>I am working through the book mentioned and in game 8 (<a href="http://www.chessgames.com/perl/chessgame?gid=1242926" rel="nofollow noreferrer">Przepiorka vs Prokes</a>) at move 4 ...P-B4, which is black moves pawn to C5.  The book states the following:  "This move is almost indispensable in Queen Pawn openings.  It is important not to play ...Kt-C6 first, as the bishop pawn must not be obstructed."  Could someone shed some light on the importance of ensuring the queen's bishop pawn is unobstructed? </p>
  
Tags: <colle-system>
Title: Clarification in the book Logical Chess, Move by Move, by Chernev
ThreadText: # Clarification in the book Logical Chess, Move by Move, by Chernev
  
  (Asked by: username_0 on 2016-12-30)
  
  I am working through the book mentioned and in game 8 ([Przepiorka vs Prokes](http://www.chessgames.com/perl/chessgame?gid=1242926)) at move 4 ...P-B4, which is black moves pawn to C5. The book states the following: "This move is almost indispensable in Queen Pawn openings. It is important not to play ...Kt-C6 first, as the bishop pawn must not be obstructed." Could someone shed some light on the importance of ensuring the queen's bishop pawn is unobstructed?
  
  **Tags:** colle-system
  
  
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  ## 3 answers
  
  ### Answer by username_1 on 2017-01-03. Score: 2
  
  Often black plays b6/Bb7/c5 to support an attack against the White d-pawn, and at times even Na6 to support c5. Obstructing the c-pawn slows down or prevents these kinds of maneuvers. Nc6 is an awkward placement of the knight on the queenside with d5/e6 being played by black, as it has no real good second move from c6 to get out of the c-pawns way, thus losing time, if black wants to follow up with ...c6 or ...c5. The move ...c5 is a "breaking" move that black wants in many openings, including the Caro-Kann, the French, etc., and not just d-pawn openings. A knight on c6 is generally speaking a 'good' knight when ...e5 and/or ...c5 has been played, i.e., king's pawn openings, The Sicilian Defense, etc.
  
  
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  ### Answer by username_2 on 2016-12-30. Score: 1
  
  One thing would be it allows you to put more pressure on d4, having both the pawn and knight hitting it instead of the pawn being blocked behind the knight on c7. The king's pawn is usually supporting the queen's pawn on d5.
  
  
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  ### Answer by username_3 on 2017-01-02. Score: 1
  
  I've often thought that the author over-emphasized this point. But there are good reasons for ...c5 in Queen's pawn openings. This single move accomplishes three things. 1. Put pressure on d4, as @username_2 has said. 2. Make room for the Queen Bishop, assuming ...e5 is not workable. 3. Create a meaningful open file for a rook--again, assuming ...e5 cannot reasonably be played. (I say "meaningful" because it is relatively easy to open *some* file, such as with the a- or b-pawn, but usually a rook on the c-file hits more valuable targets, and besides, it is usually important to prevent White dominance on this file.)
  
  
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