[helene_t]

onoway, on 2012-November-06, 14:42, said:

Isn't a new suit by responder forcing one round?

Not when partner has shown a balanced hand and/or shown tollerance for unbid suits by doubling. 3♦ isn't really a new suit, it is a suit in which partner is expected to have some length.

Compare to
(2♠)-2NT-(pass)-3♦*
Assuming this is natural (not a transfer or something), it is nonforcing.

In the original problem, there isn't much need for a forcing 3♦ bid, either. With a good hand in context (5-8 points) you can bid 3NT, cuebid, or jump. 3♦ is useful when you have a very weak hand with 4-5 or 5-5 in the pointed suits.

[cloa513]

Given East has so much defence and possibly too strong for 2NT but 3NT is big gamble- he really should double again after all it vul again vul so 2 tricks down is all he needs.

[helene_t]

It would be great if double was penalty but it isn't. It is unthinkable from East's perspective that W will convert a double so his best choice is to bid 2NT.