To me, 5S with this hand is plenty. Thinking about the grand is over-optimism in my book. I just want to find the right trump suit and strain. If partner bids 6C over 5S, I will very happily pass. If he passes, I suspect we are in the right spot. Maybe even too high already. If he bids 5NT asking me to pick a slam, now I can invite the spade grand and clue him into the H void by bidding 6H.

I think Joe’s analysis furthers the case for 5S. If six makes about 2/3 of the time - partner will bid it in the vast majority of those cases. And we’ll still be able to go plus in the others.

I ran three 200-deal simulations on this problem (not a lot of deals, so the numbers I am giving are not exact — see below for details of the specifications if you are interested), using Deep Finesse, where everyone plays double dummy. My hunch is that on this type of problem, especially with the heart void, playing double dummy slightly favors the defense, who always find the best lead. Of course it is also nice for declarer never to lose to Qx or K alone and always guess the bad breaks.

Six spades makes about 64% of the time and 6 clubs makes about 55%.. About 8% of the time 6 clubs makes when 6 spades goes down (obviously when opener has long clubs and short spades). Seven makes about a quarter of the time, slightly more often in spades (about 28%) than in clubs (about 24%).

I think Drew’s approach is sensible and practical. 6S is the best guess for a contract and, as he said, you have some chance of getting to a grand. 5NT brings clubs into play, but I might have a singleton heart and do that (and do I promise only 3 clubs — I think so but this is a matter for partnership discussion). What does it mean to bid 5NT and then correct to 6S (maybe a great hand with a singleton heart)? The real lesson: pre-empts work.

[details of the simulation: I made the hand we were given South. I gave N 12-19 HCPs, fewer than 5 hearts or spades, 2-5 diamonds, 3-7 clubs, and more clubs than diamonds (C>D). East, the overcaller, was allowed 7-15 HCPs, 5-6 heats, H>S, and H>=D. West had 0-8 HCPs, 5-6 heats, and at least 2 points for distribution (where doubleton=1 and singleton=2).]