Underestimating your Opponent's Threats

"Threats are harder to see than captures. Some moves threaten checkmate, some threaten captures, some involve a general improvement in position. Some threats are crude, brutal, obvious. Others are unbelievably subtle in their intentions, refined in their execution. Some threats are sound and directed toward winning the game. Others are based on a foolish idea and will prove disastrous for the player who has devised them. Some threats are irresistible, others can be topped by a stronger threat.

In a game between good players, threats and counter-threats are essentially a matter of interplay of ideas and intentions. If each player does not always see through his opponent's threats, he is at least prepared for them. Thus, as in the case of captures, it is important to realize that threats are always possible, that they must be looked for. That is why threats are most dangerous when they are devised by an opponent who seems to have a lost game. When victory seems within your grasp is just the time when you are most likely to underestimate the other player's resources. "Simple" positions, too, are the downfall of many a player who feels that the game no longer requires careful scrutiny. Overconfidence is unquestionable the quality that leads many players to overlook their opponent's threats."          

(Fred Reinfeld, 1910-1964)

Observe the position below, all that Black sees is that one of his Bishops is attacked, and that he can capture the advanced Knight if he wishes. Yet White threatens one of the most starling brilliances ever played on the chessboard. Can you see White's threat and how to meet it?