rogerclee, on 2011-January-18, 11:09, said:
5N can work, I don't think it's terrible, in fact it's probably good opposite diamond 1 suiters and hands with 4M+5♦, but I am just not that optimistic.
That's all true, but I still think it depends on RHO. 1♦-4♣ is a great preempt, so there is little reason to stretch to bid 5♣. If RHO has a 9-card suit with no trump loser, we are getting only 300 (or +100 if we do lack an outside ace). If RHO is 8410 we are probably also getting +300 only.
So it might be the percentage play to bid to a 30% small slam, and it probably is percentage to bid a 40% small slam. If RHO would bid 5♦ with 8320 or 8311 hands, then we should probably double.