Originally posted by exigentsky
2. The Grunfeld involves primarily a dark squared strategy.
Here's an example of what I meant by light square strategy, from wikipedia:
"The main line of the Grünfeld, the Exchange Variation (ECO codes D85-D89), is defined by the continuation 4.cxd5 Nxd5 5.e4. Now White has an imposing looking centre - and the main continuation 5...Nxc3 6.bxc3 strengthens it still further. Black generally attacks White's centre with ...c5 and ...Bg7, often followed by moves such as ...cxd4, ...Bg4, and ...Nc6. White often uses his big centre to launch an attack against Black's king. One subvariation, frequently played by Karpov, including four games of his 1987 world championship match against Kasparov in Seville, Spain, is the Seville Variation, after 6....Bg7 7.Bc4 c5 8.Ne2 Nc6 9.Be3 O-O 10.O-O Bg4 11.f3 Na5 12.Bxf7+, long thought a poor move by theory, as the resultant light-square weakness had been believed to give Black more than enough compensation for the pawn."
This might be semantics, but openings where Black plays ...d6 and follows up with ...e5 or ...c5 (pressuring d4, a dark square) such as the King's Indian, Old Indian, Pirc, ...d6 lines of the Modern, Benoni, and the Sicilian Dragon are associated with dark square strategies.
Openings where Black plays ...d5 to contest the light square e4 such as the Caro Kann, the Gurgenidze variation of the Modern (where Black fianchettoes but plays ...c6 and ...d5), and the Gruenfeld (especially the exchange variation, the variations with ...c6 and ...d5, and the Prins variation) are more often associated with light square strategies, as cited above.
And even in the above example, it is clear that Black is getting in ..c5 with pressure on d4 (a dark square), so there is much going on with both color complexes, in spite of the reference to light squares, so it's not a simple issue.
The Gruenfeld is complicated, and play can go either way, especially if the Gruenfeld players gets the opportunity to play ...c5 as well, which usually indicates that Black has a good game.
At the risk of being facetious, it is certainly not a "black and white" distinction!