After the Dustbin 1NT response

Partner opens 1♠. You will have to respond 1NT with a wide assortment of weak (6-9 point) hands (that fail the Rule of 14: the points in the hand plus the cards in the long suit not reaching 14). For example:

The aim of the 1NT response is to keep the bidding open for partner in case she has a big hand, but not take the partnership overboard if she has a more normal hand. Say she now rebids 2♦, to show five spades and four diamonds (at least). What do you bid now with the above hands?

    1♠-1NT-2♦-?
 

With Hand (a), you may be tempted to bid 2NT. Don’t – such a bid would show 10-12 points. You can’t have a 6-9 point hand and a 10-12 hand simultaneously. Nor should you try 2♥ – if you go via the dustbin 1NT and bid your own suit, you should (95%) have six cards (and never, ever, four cards). You could pass 2♦, but there are two good reasons for going back to 2♠. Firstly, A 5-2 (spade) fit is easier to handle than a 4-3 (diamond) fit. 4-3 trump fits are notoriously tricky, because six missing trumps rate to split 4-2 and this will draw all your trumps (whereas you’ll have a spare trump if you have a 5-2 fit). Secondly (and this is the more important reason), bidding (2♠) gives partner another go, should she have a good hand – she could still have as many as 17 or 18 points. Note your 2♠ bid should be regarded not as happy support but reluctant preference, typically with a doubleton spade.

With Hand (b), you should bid 2♥. This shows (normally) six cards, and a weak hand, about six or seven points, so opener will very likely pass – even with a singleton heart. Note that if you’d have fallen into the trap of responding 2♥ straight away (not 1NT), the bid would be 100% forcing; opener would perhaps have rebid 3♦ and you’d likely be overboard. Hence why the dustbin 1NT is such an important slowing-down manoeuvre.

With Hand (c), you may have baulked at bidding 1NT but bid 1NT you must. Don’t think of it as a proper notrump bid; it is merely a slowing-down manoeuvre on a weak 6-9 point hand that fails the Rule of14. Over partner’s 2♦, you’ll bid 3♣, and by going up to the level of Three, you’ll often have a seventh card, or you’d have preferred one of partner’s suits at the Two level.