I had a difficult slam decision in the first match of the Sunday swiss teams at the Marin sectional.
At favorable vulnerability, Bob, as dealer, opened 1C and I responded 1S with this hand.
Partner rebid 2C and I had to manufacture a forcing bid, so I bid 2D. (Some pairs play this bid as artificial and forcing so they can handle just this type of situation. We didn't have that specific agreement, but have decided to add it.)
Now Bob made a key bid: a jump to 3S. This should show a good hand (within the constraints of his previous bidding) with 3 card spade support. Now I have a serious decision to make.
I review the bidding and try to picture partner's hand: at least 6 clubs and 3 spades. I note that I certainly have the red suits covered. I consider whether we would be safe at the 5-level if a blackwood bid didn't elicit the response I hoped for. I have 7 losers, but my long spades, red suit controls and partial fit in clubs convince me to move toward slam.
In response to 4NT, Bob bids 5S, showing 2 key cards plus the queen of trumps, and I bid 6. LHO, after asking about my diamond bid, leads the king of diamonds.
At first glance, this slam looks pretty good. As long as there is not a terrible layout in the club suit (RHO holding AJ10, A10x or the like) it should come home.
I win the ace of diamonds, play ace and king of hearts and ruff a heart high. I now draw trumps and lead a club to the king with the ace winning on my right. (I am careful to leave the diamond on the board in case the club king wins and I need a way back to my hand to lead clubs a second time.) RHO returns a diamond which I ruff. When I eventually lead another club, the jack is played on my left as clubs break 2-2.
Plus 980 was worth 11 IMPs as the opponents didn't bid the slam. Note Bob's jump to 3S which encouraged me to look for slam. Be on the lookout for opportunities to make descriptive bids to help partner.
See you at the table!