Pawn Chains

A group of pawns that protect each other on a diagonal is called a pawn chain. The only unprotected pawn in the chain is the base pawn at the back. Pawn chains can restrict the opponent's pieces and help each other advance in the endgame.

Black is attacking the base of White's pawn chain - the d4 pawn. How can you defend this pawn and add two pawns to your pawn chain?

White now has a pawn chain from b2 to e5, controlling important central squares.