Monday Dec 30 Board 27
Bidding is 1S - 2S. Modern practice is to open 1D on South's hand, because it allows a 4-4 fit to be found in either major. Also 2S by North is very brave (I would not try it, even non-vulnerable) and it certainly fixed E/W on this hand. East will pass over 2S, and West needs another K to re-open with a double.
West leads the C9 won by the CA. A heart is played to HQ & HK, and a heart is returned, won by HA. West leads another club to CJ which Declarer ruffs. Declarer now tries for a heart ruff, but East over-ruffs.
Now it is necessary for East to play the CK. This is not easy to see, but the key is to recognise that there is no entry to Dummy to play an established CQ.
If the CK is played, Declarer will have 3 choices.
(a) ruff with the CA. (It would help, but seems very unlikely.)
(b) discard. (It also helps, but seems unlikely.)
(c) ruff small, which is by far the most likely but is the poorest option.
Assuming (c), Declarer is likely to try for another heart ruff since he does not know the trump situation, and in any case a diamond looks wrong. He may cash a top trump first, but that will probably not change his play. (Although it is best to cash the 2nd top trump before ruffing the heart, that is not immediately obvious) .
The 4th heart is ruffed and over-ruffed and a trump returned (East knows the trump layout exactly). A diamond is won by the DJ and another diamond by the DK. A trump is returned, and East will win the last 2 tricks.
Declarer just makes CA and 4 trumps - 5 tricks. He had opportunities to make 1 more trick, but probably missed them.