North reasonably decided not to emphasize his fifth heart at his second turn, because of his poor suit and 5-3-3-2 shape. Thus, much as in yesterday’s deal, North-South eschewed the 5-3 fit to arrive in the superior no-trump game.
Declarer won the diamond lead in hand and chose to play a heart to the seven and 10. This is not the best approach since it leaves declarer with a potential guess on the second round. It would have been better to win the diamond lead in dummy and run the heart nine. As it was, though, this made no difference in the heart suit itself.
East won the heart 10 and returned a diamond, so declarer was in control. He could set up the hearts for three tricks to go with three spades, two diamonds and a club.
East missed a chance there, albeit a difficult one. If he switches to a club at trick three, declarer must duck lest he lose two club tricks, but then West can revert back to diamonds. Two hearts, two diamonds and a club are enough to set the game. From East’s perspective, he knew West had only four diamonds after the fourth-highest diamond five lead, but he could still not tell if West had the diamond ace and club king or diamond king and club ace. In the latter case, a diamond return could be essential.
The best defense would have been even harder to find if declarer had started with a heart to the king at trick two. West must duck that; the club shift has to come from the other side of the table to achieve the desired bait-and-switch.