The only thing he had to fear was a very bad split in the heart suit.

He won with the jack, discovering the bad split, and led a heart to his queen.

With the bad split revealed, she took two spade winners and the heart king.

North should have reasoned that two hearts was certainly a 6-0 fit facing a bad split.

This was covered by the jack and queen, revealing the bad split.

Now another trump lead to the king revealed the bad split, and the problem was to neutralize West's heart eight.

But he had to think again when a diamond to the king revealed the bad split.

Similarly, the chance of a bad split in a suit was greatly reduced.

This made it likely that there would be a bad split in one of the rounded suits.

South won with the ace and led a heart to the king, discovering the bad split.