E     S     W    N

The bidding was   P     1D   P    1S

     2C   2D   P    6NT

North expected partner to have a 6-card diamond suit. Also, since East's overcall in clubs suggested none of South's points were in clubs, South should have at least one major-suit K. Hence, 6D looked to be a good contract, but an opening club lead would be certain and 2 clubs might be lost. Further, if North were to be the Declarer, there might be a very favourable lead. So North bid 6NT rather than 6D.

The lead of the CA or a small heart, allows Declarer to make 12 tricks - 6 diamonds, 4 spades and 2 in the other 2 suits. So assume a neutral lead of a spade or a diamond.

Declarer expects East to have CA and HK for his overcall. So the heart finesse must not be taken. 10 tricks can be taken in spades and diamonds which will leave Declarer with HAQ and CK. East may hold (a) HKx and CA or (b) HK and CAx. If (a), then Declarer can throw East in with the CA to lead back a heart to Declarer's HAQ. If (b), Declarer can cash the HA, dropping the HK.

So Declarer must watch East's discards to judge whether he ends with (a) or (b). For the Defence, East has to realise before trick 10 what is happening, and try to discard in a way which might mislead Declarer. Discarding the HJ at trick 10 while still keeping the HK8 is probably the best approach, but it means bearing the CA early and it is essential that West does not throw all his clubs.