Figure[Black to move]

Black is mated. See how the knights and bishop are coordinated; consider the work they are doing one piece at a time. The e5 knight seals off the squares on either side of the king. The bishop takes care of the squares behind and in front of it; and then the knight on d5 attacks the king’s current square and f6. This quick mate in the opening moves is unlikely to occur in your games, but the idea it represents is common: a knight jumping out of a relative pin, appearing to sacrifice the queen behind it—but then creating a mate threat that wins material (as described at the end of the previous frame). This is generally known as Legall’s pseudo-sacrifice.

Notice that a dark-squared White bishop on, say, g5 can perform the same function as the d5 knight in the pattern shown here, attacking both the Black king and the f6 square. It wouldn’t quite work here because Black could interpose his knight on f6 to block the check; BxN+ would then be unsafe (we're assuming White’s d5 knight is off the board). But in cases where the queen’s knight is off the board or out of position, it sometimes is possible to achieve the same effect seen here with two bishops and a knight instead of two knights and a bishop.