Learn How to Spot a Mate in 1: Corner Mate
This puzzle is a classic middlegame tactical finish from the Queen's Gambit Declined. The key idea is a corner mate: the enemy king is boxed in by its own pieces and has no safe escape squares. In positions like this, material balance matters far less than king safety. Even when the board looks roughly equal, a single forcing move can end the game immediately if the king is trapped and the mating square is protected.