Opposition With Room: The d5 Breakthrough

Opposition is the most quoted idea in pawn endings and the most misunderstood. Holding it is worth nothing on its own. It is worth something only when the board gives you somewhere to go with it.

Only d5 wins. The move looks like a gift, because Black replies cxd5 at once. It is not a gift: after Kxd5, also the only move, the pawn left on the board is the b-pawn, and your king stands in front of it with the black king obliged to give way.

Then outflank. Kc5 is again the only winning move, and after Kb7 only Kb5 keeps it. Once the kings are locked, White walks around the side the defender cannot cover.

The edge version is a draw. Our position "The Opposition Is Worthless Without an Outflank" is the identical structure pushed one file toward the a-file. There the defending king has the edge of the board at his back and White has nowhere to walk around to. The whole difference is a single file of space.