This is aHand:

Bidding.

Partner opens 1NT (15 to 17) after West Passes as dealer and we have to find a response.

With five Hearts it might be right to play in 4♥, it might be right to play in 3NT – much depends on partner's Heart holding. Our most descriptive bid is 3♥, telling partner we have a five-card suit and game-going values (10 or more points, essentially).

Partner has to choose the resting spot and, with four-card trump support, naturally chooses 4♥ over 3NT.

Play.

West leads the ♣Q, the top of a sequence, and we settle down to Count and Plan after dummy is displayed.

On this deal, we need to recognize the danger of attempting to draw trumps at trick two. The danger is the player with the ♥A might win the Ace of trumps and lead a Spade, and we may end up losing two top Spades, one top Heart, and a slow Club trick for down one.

[Note: In point of fact, the defense could have beaten us by leading a Spade at trick one, but West (not having second sight) can hardly be blamed for his choice of opening lead].

The solution on this deal is to dump a loser quickly. After winnning the Club opening lead on table we must immediately switch our attention to Diamonds and play three rounds of the suit to discard a losing Spade from the closed hand.

This discard reduces our Spade losers to one and, in conjunction with a Heart loser and a Club loser, we will lose at most three tricks. Only after this emergency procedure is it safe to extract the opponents' trumps. 

This deal is all about appreciating the danger that we are in. How? By counting (it's a familiar theme, no?) Here we count losers and see that we have one too many.

So we need to appreciate the need and the method for ridding ourselves of an excess loser ASAP after the unfortunate opponents have failed to hit us in our weak spot.