jogs, on 2016-September-11, 18:48, said:
Doesn't this line of defense allow 4♥ to make?
You lose 1 spade, 1 diamond and 1 club. Can't pard set up the diamonds for the 10th trick?
You lose 1 spade, 1 diamond and 1 club. Can't pard set up the diamonds for the 10th trick?
You lose 1 ♠+1♣+1♠ ruff by W (or trump promotion) and 1 ♦
He started with ♠A.
And then cashed ♣K. I think West now should have find a way to highly discourage the clubs.
How would East know declarer had 5 spades?
I think he already knows from the auction that N holds at least 4 spades. (pd did not raise spades, holding an Ace, so he has at most 2 spades) If pd is discouraging clubs, he wants spade because he would not ask for diamond. They always take their diamond trick if they have one. As Ken said it is still not easy from East to find the defense even if East knows that West ruffs 2nd spade. Because he also needs to know that he can not cash 2nd ♣, which would be needed if declarer discards 2nd club from dummy on 2nd spade while pd ruffs and when declarer has Q of diamonds.