Lesson
White to move. Main line: 1. Rc7+ Kg8 2. Rxd7
Rc7+ is a clearance move. Once the rook leaves c2, the bishop on b1 sees through c2, d3, e4, f5 and g6 to the king on h7. The discovered check prevents Black from moving the attacked queen.
The rook’s destination matters just as much as the square it clears. From c7 it attacks d7, so after the forced ...Kg8, Rxd7 wins the queen. A random rook move off c2 would open the bishop but gain nothing afterward.
Clearance tactics have two coordinates: the square that must be vacated and the useful square the clearing piece should reach. Calculate both before moving, and prefer a destination that attacks material while the discovered line supplies tempo.