IMJohnCox wrote on 11/22/11 at 01:03:27:


But to play my own devil's advocate here: it weakens d4, but it strengthens d5. It blocks the bishop's b3-f7, but it opens c2. Where is the bishop going to go anyway if black plays e6? 
   
SWJediknight wrote on 11/22/11 at 14:33:37:


I agree it does become really closed. 

tp2205 wrote on 11/22/11 at 12:13:32:


d5 can be a good move with the bishop on b3 or c4 though, such as in very similar positions in the Italian game. If black tries to dislodge the pawn it opens up the bishop diagonal. However unlike in the Italian game the bishop cannot switch and attack h7 if black is fianchettoed. But in general d5 needs less circumspection than e5 at least. 

Thanks for the input so far. Very interesting replies.

fling wrote on 11/22/11 at 08:53:31:


Just two additional remarks.

1) In this case I think it is not so much the support which is the problem but rather what are you going to do with it. Here it does not help you to reroute your pieces quickly from one wing to the other nor does it lead to some interesting pawn breaks.(Especially after the suggested further moves e5 d5 c5)

2) The fact that you do not have the pawn break c3 any longer may not seem like a big deal, but having such an option restrict your opponent because pieces are tied to defending (or at least be prepared to defend) critical squares. The more you reduce your own options the easier it gets for your opponent to react to all your plans.

Worth noting that a 0.25 or so downgrade in a computer evaluation really isn't a terribly dramatic event You've still got an entirely workable position after it, just perhaps not quite as nice as before.

I don't think c4 e5 d5 c5 is bad for white as such - he's allowed to play on the kingside too. Pieces not that optimal for this of course - you've got to get in Bc2, free the f pawn, find something to do with the (unhappy!) b1 knight etc.

As for downgrading from +0.35 to +0.08 of your engine evaluation, it is clear that the engines are made to evaluate not only the space taken by your pawns.. The main reason here can be the counting of squares that your bishop on b3 is attacking after c2-c4. The mobility of the pieces is a major part of engines evaluations, too.. 

c4 can't be that bad, though that square could be useful for the knight instead. You also block your own bishop on b3. But the two advantages that really stand out for White in the position is firstly the lead in development, and secondly the opportunity to break open lines on the queenside with c2-c3.

c3 immediately looks interesting, and would be my first thought. It doesn't look like White can gain anything quickly from his lead in development (like keeping the black king in the centre), but it does mean Black wants to avoid the position opening up until he's caught up. Moves like Bg5 and Re1 must be reasonable.

Btw. I definitely don't think you should meet c4 e5 with d5, since Black could then close the entire queenside with ...c5 when your lead in development becomes meaningless and Black can aim for a good King's Indian.