Now it gets a little more interesting. The two sides have a knot of pieces in the middle of Black’s end of the board. How can White take advantage? Look for pins. The important point to see is that White’s rook on c7 pins the Black rook on d7. The next thought is to try to take the pinned rook, but you see that this cannot now be done because the rook is protected as many times as it is attacked: twice each way. You think about adding more pressure against the pinned piece with, say, 1. Qb5; but you have to consider Black’s options as well as yours, and with so many pieces clustered in the picture it’s not surprising that he has his own resources to try: he can play 1. ...Rd7xRc7. The pin is removed, and if White plays QxQ Black just replies RxQ. Lesson: if the enemy’s pinned piece has the power to take your pinning piece, ask what the consequences of that defense would be.
Since immediately adding pressure doesn’t work, a next thing to consider is a preliminary exchange of the pinned piece to simplify matters: White starts with 1. Rd6xRd7+, and Black is forced to reply Rxd7 unless he wants to just let go of the rook. The pinned piece is left attacked once and defended once. Now try adding 2. Qb5. This time it works: if 2. ...Rd7xRc7, White plays 3. QxQ—and Black’s queen is lost since it has no defender. (Notice that Black can’t play the defense 2. ...Rd1+ followed by QxQ after White fends off the check; the rook on d7 remains pinned to its king.) In effect the Black rook ends up in a cross-pin, pinned to its king by White’s rook and to its queen by White’s queen. We will study more examples of cross-pins later. The point for now is to see how taking the pinned piece and calling for its replacement can improve your ability to put decisive pressure on the pinned position.