The convergence pattern

 Plans are based on moves that are irreversible: a pawn move or a piece trade. Whenever a piece is exchanged or a pawn is moved, you have to reconsider your plan.

The motivation for a pawn move lies in changing the piece activity. Piece activity comes in two flavors:

• Increasing the activity of your own pieces
• Restricting your opponents' pieces

In order to get the hang of pawn moves, you must develop an eye for convergence squares. A convergence square is a square which can act as a pivot point for pieces.

White to move

r3k2r/ppq1n1pp/2nbbp2/2p5/2PpPP1N/3P4/PP1N2BP/R1BQ1RK1 w kq - 0 12

• e4 is a convergence square for the white pieces (bishop and knight)
• e5 is a convergence square for the black pieces (bishop, knight, queen)

Both squares are currently blocked. The manoeuver 1.e5 fxe5 2.f5 clears e4 while blocking e5 permanently. The cost is a pawn, but it takes black 4 tempi to redeploy his pieces to active squares. I read somewhere the rule of thumb that a pawn is worth 3 tempi. Stockfish deems this as +2.83.

See how the scope of the pieces on both sides has changed!

After 2. ... Bf7. White to move