Board 16 on Thursday November 29 is interesting.
If West passes, North will probably play in 4S (1NT - 2C; 2S - 3S; 4S). East will probably lead the DJ, and Declarer will go 2 down. (West will take two top diamonds, and then lead the D5, his lowest diamond, for East to ruff and return a club which West ruffs. East will make one more trump.)
However, West may open the bidding with 1H. (My partner did and I agree with him.) There are 3 possible bids for North, although many will reject one, or even two, as wholly wrong.
Pass is possible, and might lead to a plus score if West goes to 3H. (Over 1H - 1S; 2D, it is difficult for North to enter the bidding.)
Double is possible, which will lead to 4S, down 2.
1NT is an overbid, but will probably lead to 3NT which should make.
Assume North is in 3NT, after West opened 1H.
East will lead the H3. Declarer's first decision is whether he should win with the HQ. It is normal to do so, to avoid a blockage, but Declarer must expect a second heart lead soon, so that seems to be irrelevant. More relevant is that West is likely to hold the CK and hence Declarer should play clubs before spades, since he may be able to develop an extra spade by ducking one to East. However, East may have the CK, so clubs should be played from Declarer's hand. Hence Declarer wins with the HA and leads the CQ covered by CK and CA.
When East plays the CK, Declarer 'knows' that West must have the DAK and the SQ, to justify his opening bid. So he is now 'sure' of his contract, and is thinking about overtricks. He plays SA followed by the S6, intending to finesse. When West discards on the second spade, Declarer has to rethink. West has 12 cards in the red suits (7-5 or 6-6).
Declarer can count 3 hearts tricks, 3 clubs and 2 spades. For his ninth trick he will now need the DQ. This means leading diamonds twice from Dummy. West will gain the lead twice, so Declarer needs his two stops in hearts. So Declarer must now win the SK, to prevent East winning and knocking out one of Declarer's heart stops.
Now Declarer must review West's possible plays when in with the first diamond. He could lead a heart to the HQ, which would not present a problem. But he could cash a second diamond and lead a third to the DQ. Now the possible blockage is relevant. Declarer needs to win the HQ and get back to hand to cash the HA. So it is vital that Declarer retains the C10 in hand as a re-entry card. He should therefore lead to the CJ and lead back a diamond for West to win with the DK. Now, whatever West does, Declarer can access all his tricks.