Figure 4.4.4.3[White to move]

A more demanding position. Look at what White attacks and you see that he has a relative pin in place: his bishop on d4 pins Black’s bishop to Black’s queen. Before White starts amassing attackers against the pinned piece, he should improve it; a pin of a bishop by a bishop is nothing much, since Black can just play BxB. It gets much better if White plays RxB, inviting RxR, for then White has given away the exchange but has a real pin of Black’s rook and can get to work ganging up on it.

The rook would start out attacked once (by White’s bishop) and protected once (by Black’s queen). The attackers need to outnumber the defenders for the piece to fall. White starts with Rc2 and Black replies Rc8, again a common rallying of the rooks on either side to the scene of the pin. Can White bring one more piece to bear? Perhaps his queen; but how? Consider Qb5. This looks dangerous because Black remains able to play RxQ, causing an exchange of queens to follow. The point to notice, however, is that by moving his other rook over to c8 Black has caused the rook on c5 to be caught in a cross-pin: if he moves it to the b-file (as by playing RxQ), White plays RxRc8+—and the priority of check means Black now will have to waste a move evacuating his king from the back rank. Then White takes Black’s queen with his bishop.

The more likely sequence after 1. RxB, RxR; 2. Rc2, Rc8; 3. Qb5 is 3. …RxRc2; 4. BxQ, Rxa2—and now Black attacks the White bishop on a7 with his rook, and also threatens Rc1+ (with his other rook), which would require White to interpose with Qf1 and thus lose his queen for a rook next move. (So notice the work done by Black’s Rxa2: aside from picking up a pawn, it also prepares Black to control both of the first two ranks with his rooks if he can play Rc1.) White can avoid all this, though, by replying to Black's Rxa2 with Bc5, taking his bishop out of danger (since it's then protected by its queen, which is still on b5) and using the bishop to block Rc1.

Yes, there's a lot to keep straight here. To understand the dymanics of the position at the end you have to keep straight a lot of differences between the board in front of you and the board as it then will look. Going over the flow of the position a few times is a worthwhile exercise in visualization.