411 REFERENCE · Wikibooks
Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6/3. Nc3/3...d5/4. cxd5/4...Nxd5/5. e4
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Grünfeld Defence rd nd bd qd kd bd rd pd pd pd pd pd pd pd nd pl pl nl pl pl pl pl pl rl bl ql kl bl nl rl
5.e4
This move greedily grabs central space. Since Nf6 or Nb6 would leave black without enough pressure in the center, Nb4 misplaces the knight only to create the obvious threat of Qxd4 followed by Nc2, Nxc3 is forced. Although d4 is strengthened, the queenside weakens, and the a1-h8 diagonal loosens up. That is why g6 and Bg7 is played in the Gruenfeld Defence. Black will now play to dismantle white's central ambitions. Usually, Black advances the c-pawn, and then he uses his e-pawn to dismantle white's center. Also, Nb4?? loses to Qa4+ Nc6 d5.
After e4, White has a dangerous center. Black must pressure it or risk a cramped, passive game. The only good move is Nxc3, else play resembles the dubious Marshall defence.
Theory table
+567e4
Nxc3bxc3
Bg7Nf3
c5=