Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6/3. Nc3/3...Bg7/4. Nf3

=Indian Defence=

4. Nf3
This Knight development is solid but leaves the options open for Black to either play The King's Indian or the Grunfeld Defence. If Black wishes to play the Grunfeld then responding immediately with d5 is required as white next move is likely to be 5. e4 which prevents d5 from being played.

Theory table
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'''1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3'''