Partner most probable hands are
5422 or 5431 or 6421 or 6412.
but each time hes got stiff clubs 4s is a much better contract then 3nt.
even if hes 5422 4s should come home quite easily.
this was the NS hands
6 d is also a fair contract but its pretty much unbiddable.
on slamish hand (where opener has extra) like 3 aces + a Q or a 6th spades or 4d.
bidding 2d work much better then bidding 3c.
and when partner has a minimum. bidding 2d seems to work better then 2c. because its allow you to play 4S instead of 3nt.
this hands was played in pairs and the result were all over the map.
some table received a clubs leads some didnt. most pairs were in 3nt.
but i believe both in IMPs and pairs 2d is the correct bid.

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