Posted 2018-October-23, 16:44
Others have explained why North knows, beyond any reasonable doubt, that declarer has the club Queen by virtue of trick one. Note that had declarer played the Queen at trick one (which is clearly the correct play....if South held J109, then North would not be sure where the Jack was, at least not at that stage), the result would be the same, since South would not play the 9 from J9x, not seeing the 10 in dummy.
Also, of course, as has been pointed out, declarer was cold on a non-heart lead once diamonds behaved....North had no business scoring a trump trick (which deprived declarer of a diamond trick).
So on the actual hand, it is trivial to defend 'correctly' after the initial lead, and trivial to play the hand for 12 tricks. Both N and W erred, in fundamental ways, and yet the score was (given the lead) par.
There will be other hands where the clues aren't as clear, and the OP is, I think, looking for help in defending such contracts.
On this hand, the simple solution is for South to think about what he knows. The lead of the low club (to which I will return, since it seems me to be a clear error), tells South that partner has at least 3 clubs and maybe 4 (assuming 4th best leads). Declarer topped the 9 with the J. Partner won't have KQ, since he would lead the King. Therefore opener has either AKJ or AQJ. He may have 3 or 4. In any scenario, South's clubs are irrelevant and everyone at the table knows this.
So it behooves him to tell partner what is going on in the suit. He does this by pitching his remaining 2 clubs as soon as possible...and from high to low, to give count. There can be no ambiguity in doing this, because he cannot be signaling attitude....his play of the 9 at trick one denied any honour. So the pitching of the 7 cannot be 'attitude' any more than following up with the 5 can be completing a 'come on'.
Once South has shown that he began with 975 of clubs, North knows that declarer began with AQJ. Of course, on this hand we already knew that. But imagine South had J75 and declarer AQ9...now South plays the J at trick one and declarer wins the Q. It may well be necessary for North to decide whether declarer began with AQ in clubs and Qx in hearts or a stiff heart and AQ9 in clubs. Since South's Jack denied any other honour (he might have had the Q but for declarer playing it!), he can again see his clubs as irrelevant and therefore go out of his way to tell partner that he began with 3...pitch the 7 then the 5.
As for the lead: when the opponents have a power auction to slam (as they, wrongly, did here....West has no business bidding 4N but probably has no clue as to how to bid good hands other than by jumping to 4N) one should tend to make a passive lead. Note that North has no reason to believe that West has long diamonds but every reason to place West with some side Aces. Lead a spade!
Not just any spade...lead a small one. If the opps have all the top spades, you aren't taking any tricks, but if partner has a stiff honour, you are (almost) sure to take a trick by leading low...the only way you don't is if dummy has HHxx in spades, and the odds are very much against that, since that means declarer used 4N with at best Axxx in spades.
Now, on the hand, the spade lead does no good, but it is still the correct lead imo. Btw, I am usually a very aggressive leader, but not when the auction tells me to go passive, as I think it does here. One could easily be blowing a trick...imagine dummy with xx in clubs...so Kxxx Axx KJxx xx and declarer with AQJx Qx Axxx AQx
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari