East opens 1S, South passes. West knows there is Game in spades, so 4S seems OK. But there might be slam if partner is a 6-loser hand. I like to play 4S as weak but with lots of trumps, kind of a pre-emptive shut-out so that partner won't push towards slam. You can make a waiting bid as West and see if partner can jump. But 2D looks funny and 2H should really promise five hearts. Let's say 1S - 2H and now East rebids 2NT showing 15-19 points. West is still interested in slam and could bid 4C asking for aces, and on to 6S. Another approach as West is to respond 5S ! "I'm good enough for Game, even more if you are strong." West could also just ask for aces immediately, 1S - 4C or 1S - 4NT, whatever you play.
(Experts play Jacoby 2NT here as a game-force in spades, so 1S - 2NT, and then East describes their hand further before they check for aces.)
Slam is cold. If South leads the C5, partner plays the Queen, setting up the King. If the heart finesse fails then N-S will also cash the king of clubs. If you're only in 4S then you take the heart finesse, 13 tricks ! If you're in 6S then you don't have to take the heart finesse to make 12 tricks. You can draw trumps, AKQ of diamonds and pitch a heart loser, conceding a club at the end.
Congrats to Angela and Mark for bidding and making the slam.
- Giles