They say that 1NT is the hardest contract to make (one of my students once suggested that your partner should always raise you to 2NT, since that contract is easier). From an online game, as South, you hold:

94
A53
AQ53
AJ64

Your 1NT opening buys it and LHO leads the 6 (standard). What is your plan?

	KJ82 76 K64 8732
	94 A53 AQ53 AJ64

This was IMP scoring, but I don't see that the plan should be any different at matchpoints. In notrump, I like to count winners. You have 3 sure diamonds and 2 aces for 5. This spade lead gives you a great chance for extra tricks. If LHO has led from the ace-queen, you can win the jack now and later lead up to the king.

Players are reluctant to lead from AQ against 1NT, so let's say you choose instead to hope LHO has led from Q10-empty. You play low from dummy and hope East produces a low one or the the ace. No, he plays the queen. That's not terrible news--at least it wasn't the 10. Now, you will be able to later build additional trick(s) in spades. Note: The Rule of 11 tells you that East had only one card higher than the 6 (11-6=5 and you can see 4 of those cards). Looking at those great spades in dummy, RHO switches. He plays the Q. And you?

Well, in my tricky way, I have glossed over the key play. Did you unblock your 9 at trick one? You will soon see why that was a good idea. Let's say you hold up in hearts and the defense plays them until you win your ace. The diamonds can wait; you want to play a spade now while dummy still has the K as an entry. If you play the 9 (which you carelessly retained), LHO plays low. Your 9 wins the trick (winning in dummy is no better), and you are stuck in your hand. When you test diamonds they don't split and you have only 6 tricks for down one.

What if you properly unblock the 9 at trick one? Your foresight makes the rest easy. When you win your A you lead your 4 to dummy's 8. Then you are in dummy to knock out LHO's A and you have 7 sure tricks. This was the Real Deal:

Vul:Both Dlr: South	KJ82 76 K64 8732
A10765 K842 107 Q5		Q3 QJ109 J982 K109
	94 A53 AQ53 AJ64

My lawyers have made me state that there is a double-dummy way (too many players out there run my deals through double-dummy software and write letters to the editor) to survive without unblocking the 9 at trick one. Still, it is the correct play and be proud of your +90 if you saw it!