EW miss out on a good heart game.

W/NS
♠	9 3			♠	A 10 7 6
♥	A Q 9 5 4			♥	K 8 7 3
♦	9 8			♦	Q 10 7 5
♣	A K 8 5			♣	3

'I don't think I should do more than invite for game', says East.
'I have thirteen points, a minimum hand for opening, so I really cannot raise to 4♥', says West.

West makes ten tricks.
Who was wrong?

Solution

West was wrong; he should not have passed 3♥. True, he has only thirteen points but these are honour points. He forgot to 'revalue' his hand.
As soon as a fit is found in a suit and if it is clear the contract is going to be played with that suit as trumps (the latter is certain in case of a major suit fit, but not in a minor suit fit) both partners can add distributional points:
- three for a void
- two for a singleton
- one for a doubleton
- one for every extra trump

East knew about the fit when West opened 1♥. He showed 10-11 points by bidding 3♥, so he apparently has added two points for his singleton.

West knows about the fit after East's 3♥ bid.
If his 1♥ opening showed at least five hearts he adds two extra points (one per doubleton) and has now fifteen. If his 1♥ opening showed four hearts only, he can add one more point for his fifth heart and has sixteen.
In both cases West is strong enough to raise to 4♥.

Note East bid only 3♥, meaning the 1♥ opening showed only four hearts. After all, if it would have shown five, East would have added one more point for his fourth heart and would have bid game himself.