black's rook captured the isolated pawn on square e4 for free as it had no other supporting pawns beside it to defend it
"in a game of chess the term "isolated pawn" refers to a pawn on either side of the board that doesn't have any pawns on its left and its right
"black's rook captured the isolated pawn on square e4 for free as it had no other supporting pawns beside it to defend it" What is the definition of "isolated pawn"?