Piece Sac creates unstoppable passed pawn

ICC handle Compassion, from Sweden, was not treated compassionately after attacking White's e5 Bishop with pawn move f6. Beginners at chess sometimes are slow to learn that pawns attack diagonally which is contrary to their vertical, non capturing, motion up and down the board.

A columnist in the Yasser Seirawan magazine wrote a marvelous article about zigzag pawn moves making captures on each move as a recurring tactical motif! The affable Syrian, who has lifetime winning record against Tal, is not nearly as active these days as the chess world would prefer. 

Neophyte lovers of the Royal Game are sometimes programmed to automatically move an attacked piece, especially when a measly pawn is the offender. However, the move pawn to f6 also made Black's second rank fatally exposed. So how does White ignore the overt threat to his centralized Prelate?

The pawn advance to b6 is a game winner only because of aforementioned weakening, otherwise the Queen e5 Bishop d6 diagonal dominance would be an adequate defense!