What is the Most Aggressive (and Sound) Defense to 1. d4?

 If you use this move order to reach th semi-slav you had better be prepared to face 4 e4 !?  the Marshall gambit which is a stern test of this move order.

there are three types of attacking . throwing everything at the king; accumulating small advantages 'sound" and being aggressive but not like in the first option

 but you can go into the anti moscow with 4...dxc4

I'm assuming that white gets nothing if he doesn't gambit the pawn.

1.d4 d5 2.c4 e6 3.Nc3 c6 4.e4 dxe4 5.Nxe4 Bb4+ 6.Nc3

 The most critical line is : 5 Nxe4 Bb4+ 6 Bd2 Qxd4 7 Bxb4 Qxe4+ 8 Be2 ........ this line is critical and both players best be booked up to play it.

In this line 8 Be2 scores 57% and 8 Ne2 scores 63% so black has the burden on him. 6 Nc3 only scores 49% so is fine for black.

Yeah, it's the most critical, but what if white plays this other way? Black still has some position problems to solve, though I would think the position's equal.

 What are you basing this on ? I am going by database stats ( at least that is something )  as well as personal experience. I have played both side of this line and its far more difficult for black to play than white. Actual results do NOT support your "black is better" , in fact it supports the opposite. In any event my contention from the beginning was that anyone trying to get into a semi-slav by the move order suggested had best be prepared for the Marshall gambit which is not easy to defend for black. I stand by that 100%.

Reb, didn't you know that Richie is the leading expert on openings on this site?

Richie, do you subscribe to weekly DB updates of all the games?

I'm a little surprised that you're so plugged in to the current market of chess opening theoretical development.

 No Ozzie, I wasnt aware of this but now I am.  What are your credential's exactly richie ?  Curious minds wanna know....... You say "improvements have been found for black that would have held" , what does this mean exactly and who found the improvements ? Rybka or some other program ? If so I would like to point out that humans cannot play as well as any of the top programs, not even top humans. So, if a comp can hold the position it certainly doesnt mean a human can with the clock ticking and all that pressure.... computers not only attack better than humans but they defend even better.... so, until actual practice ( between humans, not comps) indicate black is better in the Marshall gambit I will just have to disagree. I think the position is extremely unclear and dont like playing either side of it really but I wouldnt say black is better when white is scoring 57% in the 6 Be2 lines and 63% in the 8 Ne2 lines.... thats nuts.

Reb, didn't you know that Richie is the leading expert on openings on this site?

 No Ozzie, I wasnt aware of this but now I am.

I'm half serious and half kidding. Richie is by no means a super GM, but I think he is set up like one and can fake it on the forums.

I guess what I'm saying is that just because he's making his points with what some would call smug hand-waving doesn't mean that they are incorrect. :-)

Richie wrote: "6. Nc3 is eminently playable and gives White a viable position (with slight advanatge) and theory is still a bit underdeveloped."

I would have called it equal. Or perhaps "easier to play for white OTB".

I've studied a bit of the Marshall Gambit of the Semi Slav, under the guidance of a few books and Rybka analysis. I enjoy playing the 8...Qxg2 line as Black. From my (limited) experience, White does not recieve enough dynamic compensation for those two pawns.

Well it just makes sense that the DB winning % is a lagging indicator of where any variation is going.

You don't need a PhD or a JD or an MD to figure that out.

Richie wrote: "There is an excellent piece on this gambit in the Dvoretsky manual, Positional Play, by Dvoretsky and Yususpov. "

When white blunders on move 7, I begin to question your judgement on what constitutes an "excellent piece". That particular piece is part of the chapter called "Sensing the Tempo", and is included as how to punish white's misstep. It has nothing at all to do with opening theory.

Richie, I am disappointed. :-(

I don't have the other books, I'm not gonna buy them with your track record at this point... (-:

Your assertion basically boils down to the statement "unclear is better than provably bad", and on that I would agree.

Well I'm not buying any more books, I have plenty. It has nothing to do with your recommendations, if it makes you happier.

I do not believe that you recall the page from memory.

Why do I need to study this material when you are ready to play me at least one game in it, and hopefully more?

richie wrote: "But seriously, A31 is a good line for Black.  As good as any other defense, really, and better than a lot of dubious ones.  Check out ECO or any other preferred and legit source....

So, I am not going to give any Albin lines, now, as my feelings are very hurt and may even have suffered some long term injuries."

Let me try to get a better idea as to how good you really think this is.

1. Do you think it would hold up in a thematic tournament?
2. Does it do well in correspondence?
3. Does black not play 1.d4 Nf6 2.c4 c5 anymore because of d5?
4. Does white not play 1.c4 c5 2.Nf3 Nf6 3.d4 because of A31?
5. Do you think black does better in this variation than in other more popular defenses to d4? (Nimzo and Slav).
6. In the list of fighting defenses to 1.d4, can you think of a better one than this?

 How often do you play in otb tournies ? When was your most recent ? When is your next ? How often do you test your rigid views otb against titled players ? You talk the talk, but do you walk the walk ?