[vladesch]

My partner and I play precision.
I am sitting south and partner opens 1s showing 11-15 and 5+S
I respond 1nt which is forcing for one round in our system.
It can be bid on hands that:
a) are weak and intend to bid 2s on the next round
b) invitational with s support and no shortage
c) invitational with 3 card s support and an outside singleton/void
d) weak with a 6+ card suit outside spades. Will bid this suit on round 2 (or pass 2c)

west now intervenes with 2c and north bids 2d

in an uncontested auction north's 2d would show 4d, 2h would show 4h, 2s would show a sixth s, and 2c would be bid on all other hands.
Opener can jump if he has a good maximum.

So the question is, is a free bid of 2d here showing a 4 or 5 card suit.
Another question which people may find a bit silly (and I do to but my partner wont listen) is what should opener bid with 7 spades and 4 diamonds.

---

[spotlight7]

2D shows a 4+ suit.

With 6-4 or 7-4, opener bids 2S with a minimum.

A third round 3D shows a 6-4 or 7-4 type hand.

[helene_t]

It shows 4.

If dbl would be take-out, maybe it denies 5-3-4-1. But other than that, it is the same as without the intervention.

[dokoko]

vladesch, on 2018-August-02, 18:44, said:

I respond 1nt which is forcing for one round in our system.
It can be bid on hands that:
a) are weak and intend to bid 2s on the next round
b) invitational with s support and no shortage
c) invitational with 3 card s support and an outside singleton/void
d) weak with a 6+ card suit outside spades. Will bid this suit on round 2 (or pass 2c)

There are many other hands that have to bid 1NT (e.g. 1444, 1435, 1525 or 0355 with say 10-11 pts).

If 1NT was actually reduced to a) thru d), there could be a case for 2♦ showing five. But it isn't, so it can't be right for opener to pass 90% of his hands.

[steve2005]

Why rush out to show a 4-card suit with max 15 hcp?
Some hands with 4♦ double will be better.
Partner has another chance to bid.
I cant think of many hands where I would want bid rather than pass and wait.