Be nice to your partner.
Be courteous to your opponents.
And enjoy your bridge!
Fourth Suit Forcing
The heart bid from West is 4thsuit forcing, asking East for more information –he could also have bid 3NT showing enough points for game and the two missing suits.
The 3 Spade rebid after 2H shows 5+ spades and the jump is a game force. With 3 spades West knows they have a fit in spades.
On a heart lead in 3NT, West should overtake the JH in hand and lead the QS, setting up the spade suit to make 1 heart, 5 tricks in spades, 6 in clubs and the ace of diamonds.
In 4S, South is also likely to lead a heart. If North wins the ace, whatever he leads back West will win and finessing the spades will give him 12 or 13 tricks.
Evaluating your Hand
Even with such good hearts South knows that 4H is unlikely to make when his partner has a maximum of 9 points. North bids a ‘dustbin’ 1NT on the Rule of 14. When South rebids 3H, even though there is a fit with a 10 loser hand, game is probably not on, and North passes.
West leads a spade (partner’s suit) and South can see 9 tricks – (7 hearts and 2 spades). If South leads a club from dummy and East doesn’t play the ace (“second player plays low”) then South makes game.