In short: A group of pawns of the same color on neighboring files, with no friendly pawns on the files around the group. A lone pawn is an island of its own.
Look at your pawns and split them into groups. Pawns on neighboring files belong to the same group. Where a file has no pawn of yours, the group ends. Each group is called a pawn island, and a lone pawn is an island of its own.
Fewer islands are better
Within an island the pawns can protect each other, or advance and do so. But every island has edges, and a lone pawn has no neighbor at all. A player with many islands therefore has more pawns that the pieces must guard, and more squares no pawn can cover. That is why fewer pawn islands count as an advantage, and a lasting one.
In the diagram the d-pawn is an island on its own. It is also an isolated pawn, and the square in front of it, d5, can become a fine post for a black knight.
Count before you capture
Every time a pawn captures, the pawn islands change. If you can recapture with two different pawns, ask yourself which capture leaves you with fewer islands. Capturing toward the center often keeps the pawns together. Read more about pawn structures and about doubled pawns.
Frequently asked questions
Why are fewer pawn islands better?
The pawns in an island can protect each other. Every island has edges with no friendly pawn beside them, and a lone pawn has no help at all. More islands mean more pawns your pieces have to guard.
Is an isolated pawn a pawn island?
Yes, an island with a single pawn.
Updated November 14, 2026