In defence, players often falter for there is too much scope for the declarer to be holding any hidden distribution or key cards that could then blow away the defence. This often makes players in defence extra cautions to make safe defence exits rather than go for those well calculated challenging moves that form the repertoire of a good active defence strategy.
Too often in the opening leads, players get a bit bogged down allowing the opportunity of an early break through slip away. For you see that the defender's one big advantage over the declarer lies in the fact that the opening lead wrests with them. Sometimes it's a do or die situation and may a time the defenders on looking at the dummy plan the second best line of attack in case their opening leads was just a shot in the air.
Good defense strategy rests on timing your defence in accordance with the bidding and then visualising mentally the possible distribution the declarer and defender's partner could possibly hold. Those who comprehend the hand in this way turn out to be more successful than others who follow their instincts and lead impulsively.
For bridge is not a game of emotion but of logic and reasoning. True, not every time will your logic or reasoning succeed for after all cards get distributed randomly and to visualise them on known odds percentages will not cater for a 100% success rate. But every reasoning lends some semblance of a strategy that can defeat the declarer if struck on the right time. Today's problem in defence is a tough cookie but if you are placed in west's seat overlooking the dummy at your right as under after you hear the following bidding:
Your hand being: You make your best opening lead of the diamond 4 which strikes a gold mine-partner winning the ace of diamonds and returning the 9D. The dummy on your left is: Having taken 2 diamond tricks, and placing declarer's weak NT hand what should be your best move in defence at this stage, and of course at a later stage too as the play unwinds.
Of course, looking to his opening weak NT bid the hand appears to be evenly distributed 4-3-3-3. You know that if declarer holds ace of hearts and not the king of clubs, you have missed the boat already for declarer's losers would now be only 2 diamonds and the king of hearts. But if he lacks the Q of hearts and has K of clubs, you have a chance and of course if partner has a doubleton diamond, its your lucky day. So do you see the best recourse for you would be to shoot back the third diamond. On a lucky day your partner could be having a doubleton JX in spades and doubleton ace of diamonds. Then a trump promotion kills the contract with a diamond ruff by partner with JS promoting your 10 of trumps. But in the actual hand, when dummy discards a heart you know who holds the KC.
First, what do you make of the diamond distribution? It appears that if partner holds 3 diamonds as appears likely, declarer has a ready made discard of the QC on the established QD, which makes the club shift quite aimless and superfluous.
What next? How about declarer's distribution? With 4 spades possibly to the ace, 3 diamonds possibly with Q diamonds leave's him with 6 to 8 high card points, possibly comprising of the ace queen of hearts or ace of hearts along with king of clubs.
Even now 2 chances remain. One is for the east to hold the ace of trumps failing with, for east to hold Q10 x of hearts declarer has serious entry problems. If he play trumps and unblocks the clubs before playing to the ace of hearts, do you know what you need to do? Yes unblock KH trickier is if declarer at trick 4, plays all of hearts. Unblocking the KH now will lace you amongst the top defenders.
===============================
West North East South
===============================
- - - 1NT
P 2C P (Weak)
P 4S 12-14
2S
===============================
===============================
1053 KQ76
===============================
K4 58652
K10642 J7
86 AQ
===============================