By Bob Klein.
Playing matchpoints in a club game, you hold, in first seat with both vulnerable:
You deal and pass. LHO opens 2♦, weak. Your partner, a very good player, overcalls 2♠. Now, while you are thinking about how many spades to bid, RHO comes in with 4♣! What is your call?
It looks like your choices are to raise spades or cue bid. Since you are a passed hand, partner cannot expect too much from you. On the other hand, your hand has the loser count of a good opening bid! (Only 2 losers in spades due to the massive trump fit, 2 losers in hearts and 2 1/2 in diamonds--6 1/2 losers.)
With the 11-card or longer fit opposite partner who has come into the auction vulnerable, I decided that this hand had too much slam potential to bid only 4♠. Since the opponents had bid 2 suits, I couldn't make a slam invite by jumping to 5♠, since that bid asks partner to go to slam if he has a control in the opponents' suit. So I had to do something else. I considered bidding 4♥, but finally decided that the best choice was to bid 5♣. This would clearly show a big spade fit and club control with interest in a possible slam. Given the 4♣ bid and my original pass, I hoped that partner would interpret this as showing a void.
My bid worked like a charm. Partner, holding:
bid 6♠, which was an excellent contract. It happened to make seven because of the particular lie of the diamond spots. My RHO led the stiff ♦ten. My diamonds were actually Q87 opposite AJ4 so the suit came in for no losers. The first trick went ten, queen, king ace so there was a marked finesse of the nine. The ten had to be a singleton since his RHO surely had 6 diamonds for a vulnerable weak two bid. Nobody else bid the slam so we got a cold top.
RHO could have made my life much more difficult if he had bid 5♣ instead of 4, holding:
I wouldn't have the cuebid available so I would have just settled for 5♠, which partner surely would have passed.