Pawn islands in chess are a pawn structure formation referring to how many groups of connected pawns are in the position. An isolated pawn is a “pawn island” of 1 pawn. Islands of 2 or more pawns are sets of connected pawns, without supporting pawns on either side.
The theory regarding pawn islands is that fewer islands is better. The ideal structure for pawns is to have one long row of pawns connected to each other in a single “island”. The worst structure for pawns is to have many isolated pawns (each one is an “island” so there are many islands).
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