Posted 2014-May-17, 04:26
As in many situations, the standard is that there's no standard!
I'm surprised by the answers saying that 3♦ is game forcing. How often does a game forcing (single-suiter?) hand crop up when partner has shown nothing and an opponent has opened the bidding? I like to double rather than overcall 2♦ on flexible hands, so for me double followed by 2♦ could be a 2452/1453 hand with strong NT values. A jump to 3♦ is a strong bid: single-suited hand, something like an Acol 2, but not forcing. On the rare occasions when the doubler has a game force in his own hand, he can start with a cue bid.