Why do so many experienced players play more hands than their less experienced counterparts? And why do they always seem to defend 3H going down when everyone else has played in 2H making?
Like the Law of Total Tricks, this subject has generated a great deal of literature. Eddie Kantar is one notable world-class player and teacher who has written extensively about forcing auctions.
Outside the heart suit declarer has five top tricks and little chance of making any more than that. His problem is therefore clear cut: how to make four tricks from the hearts.