Slav or Semi-Slav...?

Hi!

I'm going to play some tournaments this summer, and I'm currently working with my repertoire as black. In general I like to play solid positions and I feel the Slav defence may work well for me against 1.d4. I'm also curious about the Semi-Slav defence, but I also know there are some crazy lines that may not fit my solid style. On the other side it might be able to avoid some of those lines and go for a solid position. Before I'm going to use a lot of time study one of these openings, I would really like to hear your opinions. Slav or the Semi-Slav?

If solid is your thing, I'd urge you to prefer the Slav.  The Semi practically begs white to blast up the center with a fast e4, which leaves black with plenty of chances, of course, but tends to erupt into fireworks.  You'll see a fast e4 against the Slav a lot less frequently, and it's less critical when you do.  (Although that's the way I play it. )

If not the Slav, perhaps the QGA with an early c6 against 3.Nf3 lines.  Petrosian played a lot of that.  It transposes into the Slav complex in those lines, and allows ...e5 against either of white's e-pawn deployments, and lends itself to c5/d5/Nf6 lines against the d-pawn specials, which tend to be pretty strong.  Ought to keep you on "solid" ground.

Pretty much ditto of what was said above.  While the names are similar, they are NOTHING alike.  That can be said in a lot of cases.  The Accelerated Dragon is NOTHING like the Regular Dragon, the Accelerated is far more positional and often leads to a Double-Rook and 7 Pawns each endgame.  The King's Indian Defense (which Black plays for f5) and the King's Indian Attack (which White plays for h4, not f4) is again, nothing alike.

Well, the Slav is meant for positional players.  The Semi-Slav for tacticians.  The question then becomes which line of the Slav.  4...dxc4 is positional, though a little more dynamic than 4...a6.  4...a6 Black takes on a more passive role, and basically says "White, Get me!", and when White fails, Black often gets the advantage if it reaches an endgame, and results in a lot of very long wins (over 70 moves) for Black.

The Semi-Slav is far more erratic.  While maybe not every line is as erratic as the Botvinnik or 6...Bh4 line of the Anti-Moscow, they are all pretty much full of tactics, whether you are talking the Moscow, Meran, Anti-Meran lines, Noteboom, Marshall Gambit, or any other semi-slav or triangle defense line.

Thank you for answering my question. Seems like I will go for the Slav defence. There are a few "crazy" lines in the Slav defence as well, mainly the Toulush-Geller gambit, but I guess there are some "crazy" lines in every opening anyway. 

You know, the Geller is aggressive by white, but it's not crazy in the way the Botvinnik Semi is.  White takes space and controls lots of those central dark squares, and tries to organize a direct assault.  Black takes his own space on the queenside, grabs lots of light squares, and tries to defend, hoping he can either give back the material with equality, or hold on to it and grind out an endgame. (Or simply break through on the queenside if white goes passive.)

It is, in a lot of ways, a very, very strategically straightforward game, and that makes it a lot easier to orient yourself than in a scattershot tactical minefield type game.