Sicilian defence question

I went on wikipedia to check out some openings today and I read about my favourite black defense... the sicilian. Anyways, my question is, why does white do  1.e4 c5 2.Nf3 d6 3.d4   


Can someone explain me why this move, (3.d4) . I have never come across it yet, yet wiki. seems to show that it's white best move: http://en.wikipedia.org/wiki/Sicilian_defense

 All variations are done with 3.d4 , as if it were the only acceptable move for white.

 Why is this, if it is, the "only" option.

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2nd Question:

Is this position bad for me?

Or how about:

If you've never seen 3.d4 you haven't played the Sicilian very long or you don't play opponents who study chess. I rarely play the Sicilian but these are the mainlines:

1.e4 c5 2.Nf3 d6 3.d4 - The Open Sicilian

1.e4 c5 2.Nc3 Nc6 3.g3 - The Closed Sicilian

1.e4 c5 2.c3 - The c3 or Alapin Sicilian

1. e4 c5 2. Nf3 Nc6 3. Bb5 Qc7 4. Bxc6 Qxc6  - "Is this position bad for me?" - It looks fine for Black. White is not playing very ambitiously.

1. e4 c5 2. Nf3 a6 3. Bc4 Nc6 4. Bd5 Qc7 5. Bxc6 Qxc6 - "How about?" - That also looks fine. Again, White's not playing very ambitiously.

Cloyescapade> "the option or position is flawed in that your queen is out early and you have already lost tempo."

1. "Your queen is out early" - Yes, probably a point for White because an eventual d4 will be tricky for Black with his queen on c6.

2. "You have already lost tempo." No. White has one piece out and Black has one piece out, so Black has not lost any tempi.

3. White's lost the bishop pair--a point for Black.

4. Black's retained his pawn structure--a point for Black.

5. White still maintains the "First move advantage"--a point for White.

3. d4 is NOTNOTNOT the only serious line for white.

The point is, black has already wasted (not wasted, used we will say), moving 2 pawns isntead of piece development. Therefore, after cd4 Nd4, white will have simplified and maintain the initiative.

Simple maths...the more you have the better you should trade down.

For example, youi have 5 developed pieces (4 minors and queen) and ur opponent only has queen, but a better structure. Say you traded your rooks for his knights, all your pawns for his bishops, and how he has little ot no developing potential and you can probably launch a quick attack.

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Exaggeration, I know, but meh. 

 I think the real purpose of 3.d4 is to open lines, not to simplify.  Simplification can effectively kill an advantage based on a lead in development.  As long as we're talking about 'simple maths,' let's look at 3.d4 in a different light.  3.d4 cxd4 4.Nxd4 means that White is spending two moves to move a pawn and move his only developed piece a second time.  Black only spends one move capturing the pawn and will develop his knight with 4...Nf6, attacking the pawn on e4.  While I prefer 3.d4 to the alternatives(yes, there are alternatives), it's not for the reason you mentioned.

As has already been pointed out, (after 1.e4 c5 2.Nf3 d6) 3.d4 is a standard move for white in the sicilian. Whole book chapters have been devoted to why white plays this, however consider two points regarding black's play:

1/ Black has not challenged white directly in the centre

 2/ Black has moved two pawns but no pieces, leaving white with a slight development lead

Therefore, white plays d2-d4, arguing that opening up the game is advantageous.

This is just a brief explanation, but I hope it is useful.

Regards,

Mark. 

www.chessmaterial.com