[squealydan]

Against a natural suit opening, after [1♦]-1♠-p-? : I'd bid 2♦ with most decent hands with 3+ spades unless there was another suit to bid (new suit forcing for us). A jump to 3♠ would be pre-emptive.

After a Precision 1♦ opener which may contain as few as one diamond, it seems we may want to bid 2♦ as a natural bid.

In which case am I right in thinking that 2NT is the bid to use to show a decent raise? Or is a pre-emptive raise redundant here given LHO is limited to 15 HCP and RHO hasn't said anything, leaving 3♠ a natural invite?

I'd be interested to see other people's defensive structures after the 1D opener.

Thanks.

[mattias]

If the opponents bid another suit, then ♦-bids by us become natural. If not, we treat ♦ as an enemy suit, so we would bid 2♦ with a good raise.

[paulg]

Before we played transfer responses to overcalls (including 1NT when they open a short club or diamond, not everyone's taste), we ignored the fact that one diamond could be short and still used 2♦ as the constructive raise. Hands with diamonds had to respond one notrump or find another bid. We do use 2NT as a good 4-card raise.

The concept that you can improve this because the opener is limited and his partner has passed the overcall is a good one. However, for some of us, the memory load is probably not worth the benefit.

[TylerE]

Treat it as natural. Yes, it COULD BE short, but it usually isn't, and I'm not convinced any other treatment has any real advantage. The 1♦ bid is not the greatest opening in the system, and, much like the 2♣ opening, you shouldn't feel any special obligation to bid.