Three pawns facing three pawns looks like a wall: nothing can pass, right? Wrong, and the breakthrough that proves it is one of the most beautiful tricks in chess. By sacrificing two of the three pawns, the third one bursts through before the enemy king can cross the board.
The mechanism: push the middle pawn into the wall. However the defender captures, you push the OUTSIDE pawn on the other wing next, sacrificing it to drag the last defender away, and your remaining pawn walks through the hole. Two pawns die so one can become a queen, the best trade in chess.
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Three pawns against three, kings far away. The wall looks solid. It isn't.
Break through the wall. Push the middle pawn.
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