Transfers
Transfers over a notrump opening shows length in the next suit and gives no information about strength. This puppet-like behavior saves bidding space. Wbridge5 implements French 4-way transfers, which involves only suit bids. This spares notrump bids for their natural meanings.
A major transfer shows 5+ cards. A minor transfer shows 6+ cards because a fit is needed to go over the next notrump.
Opener’s rebids
1NT opener’s rebids
A 1NT opener always accepts transfers because playing a 2-level suit contract with a 7-card fit is acceptable.
Opener may super-accept with 18+ points and 4+ cards to counter-invite responder.
- Acceptances: 1NT - 2♦ - 2♥, 1NT - 2♥ - 2♠, 1NT - 2♠ - 3♣, 1NT - 3♣ - 3♦
- Super acceptances, 18+ points, 4+ cards: 1NT - 2♦ - 3♥, 1NT - 2♥ - 3♠, 1NT - 2♠ - 2NT
- Maximum, 17 HCP, 3-card support: 1NT - 2♦ - 2NT, 1NT - 2♥ - 2NT
There is no super acceptance for diamonds due to lack of bidding space.
2NT opener’s rebids
Opener may have a singleton with 4-4-4-1 pattern. As a result, a 2NT opener tries to reject a transfer with a singleton. The Wbridge5 AI also rejects some transfers with a doubleton.
Transfer to hearts 3♦
Transfer to hearts is always accepted, even with a singleton.
| 2NT - 3♦ - | |
|---|---|
| 3♥ | Acceptance |
| 3♠! | Super acceptance, CTRL, 22+, 4+♥ |
| 4♣♦! | Super acceptance, CTRL, 22+, 4+♥ |
| 4♥ | Super acceptance, all suits controlled, 22+, 4+♥ |
Transfer to spades 3♥
Probing Wbridge5 5.12 shows that opener rejects with a singleton, or with a doubleton and 22+ points, e.g. ♠Q10 ♥A6 ♦AKQJ2 ♣A1093.
| 2NT - 3♥ - | |
|---|---|
| 3♠ | Acceptance, 2+♠ |
| 3NT | Rejection, 1=♠ or (22+, 2=♠) |
| 4♣♦♥! | Super acceptance, CTRL, 22+, 4+♠ |
| 4♠ | Super acceptance, all suits controlled, 22+, 4+♠ |
Transfer to clubs 3♠!
Rejection with doubleton makes sense because acceptance is a mediocre 4♣. There is no super acceptance because a normal acceptance already shows 3+ cards with which responder seldom passes.
| 2NT - 3♠ - | |
|---|---|
| 3NT | Rejection, 1–2♣ |
| 4♣ | Acceptance, 3+♣ |
Transfer to diamonds 4♣!
Opener is forced to accept due to lack of bidding space.
| 2NT - 4♣ - | |
|---|---|
| 4♦ | (R), forced acceptance |
| 5♦ | Super acceptance, 23+, 3+♦ |
Second responses to a 1NT opener
Opener always accepts transfer even with only 2-card support. Therefore, 6 cards are required for responder to assume a fit.
Transfer to hearts 2♦
Relay 2♥
The special 1NT - 2♦ - 2♥ - 2♠ auction shows a weak hand with 5+ cards in both majors.
A new minor shows 5+ cards. Probing Wbridge5 5.12 shows that responder rebids 3NT with 5-4.
| 1NT - 2♦ - 2♥ - | |
|---|---|
| 2♠ | 0–8, 5+♠ |
| 2NT | INV, 5=♥ |
| 3♣♦ | FG, 5+# |
| 3♥ | INV, 6+♥ |
| 3♠! | SPL, S/T, 16+, 0–1#, 6+♥ |
| 3NT | FG, 5=♥, no slam interest |
| 4♣♦! | SPL, S/T, 16+, 0–1#, 6+♥ |
| 4♥ | S/O, 6+♥ |
Super acceptance 3♥
Responder bids game with all former invitational hands because opener has shown maximum. Moreover, responder can upgrade some weak hands because of the 9-card fit.
Other bids are slam tries because a good major fit is already found.
| 1NT - 2♦ - 3♥ - | |
|---|---|
| 3♠! | S/T, CTRL |
| 3NT | FG, BAL |
| 4♣♦! | S/T, CTRL |
| 4♥ | S/O, strong enough to play |
Transfer to spades 2♥
Relay 2♠
The special 1NT - 2♥ - 2♠ - 3♥ auction shows a slam try with 5+ cards in both majors.
| 1NT - 2♥ - 2♠ - | |
|---|---|
| 2NT | INV, 5=♠ |
| 3♣♦ | FG, 5+# |
| 3♥ | S/T, 5+♥ |
| 3♠ | INV, 6+♠ |
| 3NT | FG, 5=♠, no slam interest |
| 4♣♦♥! | SPL, S/T, 16+, 0–1#, 6+♠ |
| 4♠ | S/O, 6+♠ |
Super acceptance 3♠
| 1NT - 2♥ - 3♠ - | |
|---|---|
| 3NT | FG, BAL |
| 4♣♦♥! | S/T, CTRL |
| 4♠ | S/O, strong enough to play |
Transfer to clubs 2♠!
The special 1NT - 2♠ - 3♣ - 3♦ and 1NT - 2♠ - 2NT - 3♦ auctions show a slam try with 5+ cards in both minors. This is the only possible case of only 5 cards in clubs.
Relay 3♣
When dissatisfied with 3NT and having a major singleton or void, responder always has a chance to escape because opener is forced. However, with 0–1 card in diamonds, opener may pass the 3NT response. Therefore, dissatisfaction must be shown beforehand at 4♦!
| 1NT - 2♠ - 3♣ - | |
|---|---|
| 3♦ | S/T, 5+♦ |
| 3♥! | FG, 0–1♠ |
| 3♠! | FG, 0–1♥ |
| 3NT! | P/C, 0–1♦ |
| 4♦! | FG, 0–1♦, dissatisfied with 3NT |
Super acceptance 2NT
After a super acceptance, responder can upgrade some weak hands to game-forcing ones.
| 1NT - 2♠ - 2NT - | |
|---|---|
| 3♣ | S/O |
| 3♦ | S/T, 4+♦ |
| 3♥♠ | Weak, previously hidden 4+# |
| 3NT | S/O |
| 4♣ | INV, 11–16 |
| 4♦♥! | SPL, S/T, 14+, 0–1# |
| 5♣ | S/O |
Transfer to diamonds 3♣!
The only rebid of opener is relay 3♦ due to lack of bidding space.
Relay 3♦
| 1NT - 3♣ - 3♦ - | |
|---|---|
| 3♥! | FG, 0–1♠ |
| 3♠! | FG, 0–1♥ |
| 3NT! | P/C, 0–1♣ |
| 4♦ | FG, 0–1♣, dissatisfied with 3NT |
Second responses to a 2NT opener
Since major super acceptances are control bids, there is no need to discuss them here. This section is focused on relays and rejections.
Transfer to hearts 3♦
Relay 3♥
The special 2NT - 3♦ - 3♥ - 3♠ auction shows a weak hand with 5+ cards in both majors. Probing Wbridge5 5.12 shows that it is rare: with weak 5-5 majors, responder bids 4♦! directly or passes 3♥.
| 2NT - 3♦ - 3♥ - | |
|---|---|
| 3♠ | Weak, 5+♠ |
| 3NT | FG, 5=♥, no slam interest |
| 4♣♦ | 5+#, dissatisfied with 3NT |
| 4♥ | S/O, 6+♥ |
| 4NT! | RKCB 0314, 6+♥ |
| 5NT! | Slam F, 5=♥ |
The slam force need not be balanced. After it, opener chooses between 6♥ and 6NT. Responder may raise to 7.
Transfer to spades 3♥
The special 2NT - 3♥ - 3♠ - 4♥ and 2NT - 3♥ - 3NT - 4♥ auctions show a slam try with 5+ cards in both majors.
Relay 3♠
| 2NT - 3♥ - 3♠ - | |
|---|---|
| 3NT | FG, 5=♠, no slam interest |
| 4♣♦ | 5+#, dissatisfied with 3NT |
| 4♥ | S/T, 5+♥ |
| 4♠ | S/O, 6+♠ |
| 4NT! | RKCB 0314, 6+♠ |
| 5NT! | Slam F, 5=♠ |
After the slam force, opener chooses between 6♠ and 6NT. Responder may raise to 7.
Probing Wbridge5 5.12 shows that opener answers 4NT as RKCB 0314 in spades on all 159 boards. With all five keys it bids 5NT.
Rejection 3NT
The Wbridge5 AI rejects with a singleton, or with a doubleton and 22+. Responder therefore needs 7+ cards to assume a fit to bid 4♠ or 4NT.
Transfer to clubs 3♠!
New suits are control bids because there cannot be a major side suit.
It is safe to transfer with a slam try with 5-5 minors because opener rejects transfer with 1–2 cards in clubs.
Acceptance 4♣
An acceptance promises 3+ cards, so a good fit is found.
| 2NT - 3♠ - 4♣ - | |
|---|---|
| 4♦! | CTRL or (S/T, 5+♦) |
| 4♥♠! | CTRL |
| 4NT! | RKCB 0314, no CTRL ♦, ♥ or ♠ |
| 5♣ | S/O |
Probing Wbridge5 5.12 shows responder bidding 4NT only without a control to show (8 of 8 boards, 9–13 HCP). It makes any control bid first, up the line. When opener asks with 4NT over responder’s 4♦, responder answers RKCB 0314 in clubs, counting the ♣K, on all 207 boards.
Rejection 3NT
A rejection shows a singleton or doubleton in clubs. Responder passes or signs off at 4♣ with a weak hand.
| 2NT - 3♠ - 3NT - | |
|---|---|
| 4♣ | S/O, 7+♣ |
| 4♦! | (CTRL, 7+♣) or (S/T, 5+♦) |
| 4♥♠! | CTRL, 7+♣ |
| 4NT! | BW |
| 5♣ | S/O, 7+♣ |
| 6♣ | S/O, 7+♣ |
After 4NT, no fit is found, but responder may assume a fit in diamonds with 5+ cards. Probing Wbridge5 5.12 shows that opener answers it as Blackwood, counting aces only, on all 226 boards.
Transfer to diamonds 4♣!
Relay 4♦
Although opener has a singleton in the worst case, there is no way to sign off at 4NT.
| 2NT - 4♣ - 4♦ - | |
|---|---|
| 4♥♠! | CTRL |
| 4NT! | RKCB 0314, no CTRL ♥ or ♠ |
| 5♦ | S/O |
Responder bid 4NT only without a heart or spade control (24 of 24 boards, 7–13 HCP). Probing Wbridge5 5.12 shows that opener answers 4NT as RKCB 0314 in diamonds, counting the ♦K, on all 170 boards.
Super acceptance 5♦
This bid prevents responder from passing the 4♦ relay but consumes too much bidding space. Responder can only bid quantitatively now.
Not probed
- Responder’s call after 1NT - 2♦ - 2NT, 1NT - 2♥ - 2NT, 2NT - 3♥ - 3NT and 2NT - 4♣ - 5♦.
- 2NT - 3♠ - 3NT - 4♦, 4♥ and 4♠: no board.
- Opener’s third call other than the answer to 4NT after 2NT - 3♥ - 3♠, 2NT - 3♠ - 3NT and 2NT - 4♣ - 4♦, e.g. the answer to 4NT after 2NT - 3♦ - 3♥ or 2NT - 3♠ - 4♣, or to the slam force.