I am learning/playing the semi-slav as black, but I still cannot decide what I want to play against 5.Bg5. So far I have been playing the Botvinnik system, and with pretty good results, but that is probably because most of my opponents avoid the mainline. The problem so far has been that if my opponent does happen to be really well booked then my losing chances are good, because I would be lucky to remember the mainlines up to move 20 or so, which is practically just scraping the surface of this theoretical minefield. I do really like the kingside pressue black gets, and the crazy positions that result from this line, and if white avoids 6.e4, black often ends up a pawn up for almost nothing.

There is something appealing about the Moscow variation though. If white plays 6.Bxf6, then black gets the bishop pair and what looks like a solid position. The line that scares me a bit is the anti-moscow gambit. Here it really looks like black is grabbing a pawn and then hanging on for dear life the rest of the game, with white getting pawn breaks and initiative all over the place. I do like complications though, and often am the type of player to grab material and defend for a while, so this may be a good choice.

Since both variations are a ton of work, I only want to learn one for now. Do any of you have experience with both lines as black? Which did you prefer and why? Or, if you are a white player, which line do you prefer to play against? Which gives white the better chances for an edge? They both seem quite good to me, maybe the Botvinnik is closer to being refuted but I think it is still played at top level. Perhaps most importantly, which is better for playing for a win with black? Not that a draw is a bad thing, it just depends on who you are playing. Please help me decide, worst case I will flip a coin, but to hear others' opinions on this would be great.

I'm sorry to ask this but what are the differences position wise between 5...h6 and 5...dxc4 (those are both openings right?)? They seem similar and I know they're not but I just want to know how they're so different.

After 5...h6, white can play a safe, quiet game with 6.Bxf6, followed up with e3 or Qb3 and play for a lead in development and control of the center, or he can play 6.Bh4 dxc4 7.e4 g5 8.Bg3 b5 which is the anti-moscow gambit. White has great compensation here, with pawn breaks on both sides of the board, a safer king, and a lead in development. Theory is extensive in this line, and it has been quite topical at top level in the last few years if memory serves me right. I am not sure where it stands right now in theory, but should be easily playable for most of us. If I played 1.d4 as white I would probably play this way, instead of 6.Bxf6. Note that in this move order, black can transpose to the Botvinnik system with 7...b5.

After 5...dxc4 6.e4, black should not try to transpose to the anti-moscow gambit with 6...h6 because 7.Bxf6 followed by 8.Bxc4 just gives white an improved moscow variation (e4 has been played in one move). Instead black has to play 6...b5 7.e5 h6 8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7, when he is down a pawn, but gets good development and attacking chances against white's king. He will castle long and push his queenside pawn mass, or attack white down the open files, while white will try to open up the black queenside and often use his kingside pawns in an endgame. There is tons of theory here, and it runs quite deep. It is fun to play and analyze, but can be a chore to remember various tactical lines.

Gonnosuke - I am not really sure what my preferences are as far as attacking or defending go. It really depends on who I am playing. The main thing is, I want a complicated game as black, where I can set problems for my opponent to solve, even if I am slightly worse, rather than play a quiet game where I have no real winning chances. The Botvinnik variation is probably the best choice for me, and I will likely continue to play it unless someone convinces me otherwise. 

About the triangle system. It really looks interesting, and it is something I don't know much about. I have heard good things about the Noteboom before as well. I want to stick to the Semi-Slav for now but maybe I will expand my repertoire to include it at some point. There is a new book coming out on the triangle system too:

http://www.everymanchess.com/chess/books/The_Triangle_System%3A_Challenging_White_in_the_Semi-Slav

Just a question though: Are there any possible transpositions from the semi-slav (through a slav move-order) to the noteboom? I have been wondering that lately, and have been hoping to punish white for innacurate move-orders somehow. Is there any way for black to take advantage of white playing 3.Nc3 instead of Nf3? My book only shows 3.Nf3 as the move-order in all the games it contains.

I think the botvinnik variation is close to being refuted. It has been analyzed a lot and with the help of computer programs as rybka and fritz 12 white has continued to find ways to keep a clear advantage. The botvinnik variation is rarely played nowadays and if black wants to play the semi-slav he should go for a cambridge springs or the moscow variation.

Thanks BigTy.

When I glance at the lines, the Moscow (h6) is probably more solid than the Botvinnik which seems to be very wild but fun too-quite a bit of sac'ing and tactics in this variation. I would love to get into a Botvinnik but when I play the QG as white im lucky if my opponent plays h6...At my level they just chicken out and play Be7 or Nbd7 which do look more natural and think they are still playing a Semi-Slav even though it becomes a QGD there... x]

I have had the same issue, I play the semi-slav, and I haven't found a line I really love when white play's Bg5. So here's my opinion:

The Botvinnik: Is risky, you will lose games simply because your opponent know's the theory better. Even if you opponent doesn't know all the theory I think white has an easier time developing, where blacks development is awkward to say the least. But it the most fun, and gives black good winning chances.

The Moscow: I haven't played this much because there is line in the anti-moscow where blacks best option is to force a perpetual check, it might be avoidable.

Lately I've tried the cambridge springs with so-so results, still learning the opening.

An excellent book covering what all has been said so far is Playing the queens gambit a quality chess publication. Excellent guide into all the variations of the QG. This is my favorite as white and I would say I'm most disappointed to see either the cambridge springs or the botvinnik. I would prefer the moscow or anti-moscow while the noteboom is real nice for white. Thats just my preference. Excellent book though if you like the topic discussed so far. Ed: More so for white.

Hm, do you remember when Shirov played 6.Rg1 against the najforf variation? Most theoreticans thinks that 6.Be3 is the critical move against the najdorf, but if a master like Shirov plays a suspect variation he would lose quite rarely anyway because he's a good player. This is the case with the botvinnik variation, many strong grandmasters have played the black side and scored well. After ten years the interests turned and most grandmasters thinks white is clearly better and the lines have been analyzed many times by players and computers. Black has scored horribly on a high level since 2006. Interests have turned to the moscow variation where there is a lot to be discovered.

What about 11...Rg8 (after g3) 12 h4 Rxg5 breaking the pin? Has that been refuted?  Doesn't it seem to in some ways take the point out of g3, because the knight could go to d5 and block the diagonal? I'm sure theory can answer that question.

thanks for posting those games. I dont think that white has accomplished very much after he plays exf6.