1♦ response
The 1♦ response usually shows 4+ cards and 6+ points. Such 1♣ - 1♦ is the most constructive auction. Because it is too constructive and shows no major, modern bridge players make many reasonable adjustments to the 1♦ response.
Wbridge5 is no exception. It adjusts 1♦ according to responder’s strength.
- 6–11 points: With a biddable major, skip diamonds unless 6+ cards or at least AJxxx or KQJxx.
- 17+ points: Bid strategic 1♦ with some hands indescribable by strong jump shifts.
Opener’s rebids
In Wbridge5, a 1NT rebid always denies biddable major because 1NT is difficult to make with average strength. Moreover, no singleton is allowed in the 1NT rebid. Therefore, responder can buy 2♠/♥ with only 5 cards.
In contrast, the 2NT rebid shows a balanced hand or 2=2=4=5. A 4-card major is allowed in a balanced hand. So descriptive can 2NT be because there is almost always 23+ HCP in the partnership. Since 2NT collects all balanced hands, the strong jump shifts 2♠/♥ contain 5+ clubs unless 2♥ with 4-4-4-1.
Beware that all these rebids are nonforcing. Responder can always pass when a game is unlikely.
The rebidding strategy is the same for all suit responses. The strategy is described in the page of major rebids for frequency and a more general overview.
| 1♣ - 1♦ - | |
|---|---|
| P | PH, 11–12 HCP, 3=♦ |
| 1♥♠ | 13–18, 4+# |
| 1NT | 12–14 HCP, (BAL or 5-4-2-2), no biddable M |
| 2♣ | 13–18, 5+♣, UNBAL |
| 2♦ | 4+♦, some singleton or void |
| 2♥♠ | 19+, 4+#, (UNBAL or 5-4-2-2) |
| 2NT | 18–19 HCP, (BAL or 2=2=4=5) |
| 3♣ | 19+, 6+♣ |
| 3NT! | 18–19 HCP, 6-3-2-2 |
A hand with 20 HCP and 6-3-2-2 is strong enough to open 2♣. Therefore, the 3NT still shows 18–19 HCP.
The 2♦ rebid is surprisingly unlimited. This unusual treatment produces good results in practice. Tactics are described in a dedicated subsection [not yet written].
Not probed
- The P row: no probe dealt 1♣ - 1♦ with opener in 3rd or 4th seat.