Never Underestimate the Power of a Freakish Fit
Those EW pairs who were prepared to bid their diamond fit to the max did well.
Board 17 from Thursday 10/05/2018
Dealer N Nil Vul
When North opens 1C, East can either overcall 1D or make a weak jump overcall to 2D. Either one will interest West enough to bid 5D and that should be done sooner rather than later. After the diamond overcall by East, South would double to show both majors (certainly so after a 1D overcall the way I play it) and North would be heading for 4H or 4S. But not if West bids an immediate 5D. Now North has a tough decision: to double or press on with 5H or 5S? The equal vulnerability would suggest taking the sure-fire penalty. East-West have the diamond suit and only one likely and one possible trick outside: the rest will depend on distribution.
As it happens the layout is such that EW are down only two in 5D and NS can make 5H or 5S, but I suggest that this is a lucky result for EW. Lucky or not, with a freakish fit like that, West should definitely bid 5D the moment East bids either 1D or 2D. Especially if East jumps to 2D, which means that either North or South has a diamond void and NS could be about to bid a slam. Therefore 5D is a standout bid. But only two EW pairs were doubled in 5D at the Hutt, for minus 300, while most others allowed NS to play in 4H or 4S. Maybe West was just counting points, not looking at the prospect of putting partner into a twelve card fit!