In present practice the principal variation of the Grunfeld is the Exchange Variation, characterized by the sequence: 1 d4 Nf6 2 c4 Nc3 d5 4 cd5 Nd5 5 e4 Nc3 6 bc3. As can be seen, White occupies the centre with his pawns, thus accepting Black's intentions. White's sixth move determines the beginning of the Exchange Variation and, in practice, the beginning of the debate about the line in question. 

According to classic principles, White would seem to have the better position, due to the presence of a strong pawn centre. Throughout the years, results obtained with the Grunfeld Defence and the unceasing analysis of the most famous GMs have overturned certain aspects of these classic principles and thus, not necessarily may the occupation of the centre with ones pawns be considered adventageous.