Figure 5.1.3.4[White to move]

Black just played c7-c5, moving his c-pawn from a loose position to a square where it has protection against the White rook that dominates the file. Count the pawn’s attackers and defenders. It is attacked twice, by White’s d4 pawn and the White rook; it is defended three times, by Black’s b6 pawn, knight, and queen. Since White can't win the pawn unless he has more force against it than Black has defenders, the position may seem secure. It isn’t. Look for ways to capture any of the guards, keeping in mind the possibility mentioned a moment ago: when a piece has multiple defenders, sometimes the defenders also protect each other; and then capturing one defender may have the effect of taking out a couple of them. Here White can force a trade of minor pieces with BxN. Black’s only recapture is QxB—but the queen was another of the c5 pawn’s guardians. Thus the single capture by White has left the pawn with one defender against two attackers. White now plays d4xc5—and if Black replies b6xc5, White has the last word with Rxc5.