(KW, June 8th)
Good anaylsis of several moves. You are already getting stronger in your analysis. Certainly Bg5 is a Candidate Move.
Before we decide which move to make, let us look at why Black made his last move, and what has changed? I think this is one of the first questions that needs to be asked every time a move is made. Here Black has eliminated some of his weaknesses (his pawns are in a phalanx formation, and adjacent rather than isolated, the holes on the c-diagonal are now behind the lines, making them very difficult to get to, the move c5 threatens to form an Advanced Salient, the Queen's Knight is now protected behind the frontlines, one dark square is being occupied by the c5 pawn and this pawn now attacks 2 other dark squares, including the key central square d4).
Certainly Black has all the space (COA Territorial Domination) that he wants, but only on the Queenside! Black made this move to shore up his Queenside, and to initiate a possible Queenside attack, and exert pressure on d4. The pawns on the 5th rank are a formidable force to deal with. This will be one of the key positions or a "Tabiya" in this game, and so will take a little more time on it. What White will do here will change the course of the game.
But before we get to the specific move,the next question I believe that needs to be asked is, where is the best position for each of Black's pieces? In other words, if I were Black, where would I want my pawns and pieces?
In the diagram below, the yellow arrows indicate some of the possible Candidate moves for Black and some of the possible plans Black may have. The big question in the current position is, how are we (as White) going to solve the QB problem that is in a lot of Queen Opening games (that is why it is highlighted in blue). This should be solved before we figure out where the QN should go.
arrows are possible Black moves that we must take into account. Let's move from left to right. The best spot for the QN is on c6. The best diagonal for the QB is a8-h1, so Bb7 is a natural, unless needed for Queenside attack, where Bd7 may be better.
The Queen's best spot is b6, threatening the entire b file and the b pawn, and being on the good diagonal a7-g1 (a dark square diagonal). This would fit in well if the KB is on c5, as they both would be lined up on the same diagonal.
To do that, the c5 pawn would need to take the d4 pawn, or move c4, forming an Advanced Salient (White doesn't want to help Black out by taking dxc5). As an alternate plan, the g7 pawn could advance to g6, and Black would fianchetto his Bishop, attacking the dark square diagonal a1-h8.
The KN best next move would be to e4 (anytime Black moves Ne4, Nbd2 is a Candidate Move for White). Let's keep these possible Candidate Moves in mind as we examine our move.
arrows are GW's proposed move Bg5, with a possible future exchange on f6, and I have added a possible e3 to shore up d4, once the QB has moved outside the White pawn chain. Black might interpose his Be7.
The advantages for White with this plan have been adequately outlined by GW, but one consideration of exchanging on f6 would be if Black retook with his g7 pawn. This would disrupt his Kingside structure, true, but he would be attacking toward the center, and strengthen his attempt to control the center, as well as open the way for the Black KB to move on the Kingside.
Also, at this stage, we are not sure whether Knight or Bishop will be better in the middlegame. But I think the biggest drawback of an exchange would be the f6 pawn would prevent White from placing his Nf3 onto e5 and create an outpost. As the Queen has a good spot to move to,
I do not think Black would retake with the Queen. If he retakes with the Bishop, White has problems on d4 and e5 (not insurmountable, but problems nevertheless), and White would have a hard time moving Ng5 as well.
arrows indicate another way to gain control on the dark squares. We move 6. b3, followed by 7. Bb2, and then e3 or Ne5, and the Bishop is on a great diagonal (a1-h8, a dark square diagonal), supporting d4 and e5, and pointing to Black's Kingside (indirectly attacking f6 and g7). Then both White's Bishops will criss-cross the center of the board.
Generally in many Queenside openings, Black attacks on the Queenside, and White's best chances are on the Kingside. Here, Black has not committed his King to castle on the Kingside, and may prefer to have him in the center of the board.
The advantages of these moves is that White contests c4, with his b3 pawn, the Bishop controls more dark squares than the Bg5 plan, and the plan puts another piece into the center conflict. Plus, by moving b3, it is less likely that Black will take on d4, as 7. Nxd4 followed by 8. Bb2 puts White in a good position, with the Knight attacking the b5 pawn, and hindering the Black Nb8-c6. The KN currently has 2 good moves to either d4 or e5, depending on Black's responses.
This whole plan hinges on what to do after Black's c4, creating an Advanced Salient. This is a matter of tactics which we need to explore more deeply. First, let's say we do nothing, and move 7. Bb2.
- Black would not move c3, as that loses a pawn. He could support that for his move 8 by 7...Qc7, but this is not the best square for the Queen. While the battle might switch to whether Black could play b4, White could play Qd2 and/or a3 with a good game.
- Black could try cxb3. White should retake with 8. axb3, as this retakes toward the center, and creates a Half-Open a file for White's QR, with a gain in tempo. One follow up move would be then 9. c4, to get rid of a Backward Pawn on a potentially Half-Open file, which after all the exchanges on c4 (bxc4, 10. bxc4 dxc4) could possibly leave Black with an isolated pawn on the c file, and opens up the diagonal for White's KB.
I believe White would have sufficient compensation for the pawn. An open b file would develop. If White decides not to do 10...dxc4, White has a couple of pawns in the center, and a good game.
Second, 7. bxc4 bxc4 would be bad for White, as there is no protection for the QB, and upon Qb6, Black attacks in 2 ways, the file and diagonal. Let's not play that.
Finally, let's look at 7. e3. This could be played, but is not really necessary in this position (unless Black fianchetto's his KB or move Qb6 next move - then it would be a Candidate Move). Better to move it all at once to e4 at some point, and attack d5.
If instead of 6. b3, we played 6. e3, that would be pretty passive, and would lock in our QB, and Black might be more likely to take on d4. So we won't play that move.
So I am recommending we move 6. b3
, ignore Black's c4, and take our chances attacking the center from the Queen flank. It will be interesting to see what Fritz does with this move.