Special chess moves are known to experienced chess players. One of them is the e-pawn advance made here in the Pirc Defense.
In the chess game below Black has forgotten to play e5 to stop the advance of White's e-pawn.
White will push his e-pawn ahead gaining space in the center and disturbing the coordination of Blacks chess pieces. The white pieces are placed on natural squares but Black's position is somewhat cramped.
Just look at the knight on d7. It hinders the development of the bishop on c8. Pawns have the desire to move ahead and grab space in the center. Now study the terrible effect of the e-pawn advance.
|1) White moves 1.e5 dxe 2.dxe||2) 2...Ng4 3.e6!|
... a push right into the heart...
|3) Black moves 3...Nde5 4.NxN NxN||4) White moves 5.exf+ Kh8|
|5) White moves 6.QxQ RxQ|
7.Bb3 e6 8.Ne4 Nxf7
|6) White moves|
White has a better position because Black has a weak e-pawn and his bishop is locked in. This bishop hinders the black rook to come out.