2...g6 with 5.e5

Against the fianchetto White builds the centre and closes it with e5: the g7-bishop bites on a well-defended pawn.

1.e4 c5 2.c3 g6 3.d4 cxd4 4.cxd4 d5 5.e5 Nc6 6.Nc3 Bg7 7.Bb5 Nh6 8.Nge2

Move by move

1.e4 – White occupies the centre and opens diagonals for the queen and the f1-bishop.
1...c5 – The Sicilian Defence: Black controls d4 with a flank pawn and creates an imbalance.
2.c3 – The Alapin: White prepares d4 so that he can recapture with the c3-pawn and keep two pawns in the centre.
2...g6 – Black prepares the fianchetto: the g7-bishop wants to press on White’s centre.
3.d4 – White builds the centre at once, since there is no pressure on e4.
3...cxd4 – Black exchanges to open the future g7-bishop’s diagonal towards d4.
4.cxd4 – White recaptures with the pawn: an ideal d4-e4 centre and c3 free for the knight.
4...d5 – Black strikes at e4 so as not to be squeezed: White must choose between exchanging and advancing.
5.e5 – White closes the centre: the g7-bishop’s diagonal runs into a well-protected e5-pawn.
5...Nc6 – Black attacks d4, the pawn that supports White’s whole chain.
6.Nc3 – The knight develops and attacks d5, forcing Black to keep it defended.
6...Bg7 – The bishop develops on the long diagonal, but for now it bites on the e5-pawn.
7.Bb5 – The bishop pins the c6-knight, the piece that attacks d4: White relieves the pressure on his centre.
7...Nh6 – The knight goes to h6 since f6 is controlled by e5: from here it heads for f5 to attack d4.
8.Nge2 – The knight defends d4 from e2 and can go to f4, contesting the black knight heading for f5.

A closed d4-e5 centre: the g7-bishop is restricted and White has space, while Black seeks pressure on d4 with ...Nf5 and the ...f6 break.

Nf4 controls d5 and contests f5 with the h6-knight; alternatively g4 takes f5 away from it.
O-O, Be3 and Qd2: d4 stays well defended and the queen can go to h6 to trade off the g7-bishop.
Bxc6 at the right moment leaves Black with doubled c-pawns: then the white knight eyes c5.
Against ...f6, recapture on f6 only if it opens lines for your pieces: often supporting e5 with f4 is better.

With the pawn on e5 supported by d4 and the pieces, the g7-bishop has few prospects.

The h6-knight wants to reach f5 to attack d4.