Semi-Slav vs. Grunfeld

Which is better - Semi-Slav or Grunfeld?

Bump

Actually I believe that the Grunfeld is a bit better theoretically.

However, the grunfeld requires an immense amount of theory, white has so many playable options all which require black to know what his doing. Also it can be avoided in various ways.

This conidered I think the semi-slav is a better choice, which comparitively gives black a range of setups he can use against whites various options.

According to this site http://www.becomeawordgameexpert.com/stats.htm, the Semi-Slav generally has a White wins/Draw/Black wins of 38/37/25.  The Grunfeld generally has a White wins/Draw/Black wins of 37/37/26.  Based on this alone, the Grunfeld appears to be slightly better but not by much.  However, I take these statistics with a grain of salt as they do not state (1) when these games were played, (2) by which players, and (3) at which events.  

Obviously, Anand playing Semi-Slav as Black to beat Topalov in a 2005 super tournament is a better reflection of the theoretical strength of that opening than some guy playing Semi-Slav as Black and losing because he blundered an en prise Knight on move 12 at a blitz tournament.  Similarly for the Grunfeld.  And without knowing more details about the sample from which those stats were taken, it is impossible to know whether we are looking only at grandmaster level games or at games where a player lost due to a reason completely unrelated to the opening (e.g. the en prise blunder).

The very important part is the 'theoretically'.

In most mainlines of the grunfeld black can get into an equal, alebit dynamic endgame. In the semi-slav it my understanding black will come close to equalising, but often white has a very slight advantage. (This is all with PERFECT PLAY)

The reason the databases do not really reflect this in my opinion is the practical (opposed to theoretical) side of the opening. The grunfeld is just so hard to play and to remember all the theory for, that often black will mis-step and hand white the win. Overall I do not think the semi-slav shares this same problem, except in a few variations.

I find that the Semi-Slav has some theory, but much of it is thematic (the ...dxc4 capture, the queenside pawn advance with ...a6, ...b5, ...Bb7 - not necessarily in that order, the restraint of the White d-pawn, kingside/queenside fianchetto).  The order that such themes appear in the various lines vary.  For instance, in the Meran, the capture and queenside pawn advance is played first.  However, in the Moscow, the kingside fianchetto might be played first before the queenside pawn advance.  Nevertheless, it is not too difficult to remember Semi-Slav lines.  Note that I do not play the Botvinnik Variation, known as one of the most theoretical lines in chess.  

I was wondering if the Grunfeld is similarly thematic - that is, it has common themes that run throughout the different variations.