Queens Indian Defense Petrosian Variation Puzzle (Rated 1159): Win Material — Discovered Attack
This Queen's Indian Defense middlegame shows how a single pawn move can transform the position by opening a line for a bishop and creating immediate tactical pressure. The key idea is a discovered attack: when one piece steps away, it reveals a stronger piece behind it with tempo. Here, Black’s active pieces are aimed at White’s king shelter and loose coordination, so the tactic is not random—it is based on piece alignment, weak squares, and an exposed bishop on the kingside.