Non-Natural System Discussion Forum https://www.bridgebase.com/forums/index.php Thu, 11 Dec 2025 02:12:51 +0000 30 https://www.bridgebase.com/forums/topic/91459-responding-to-a-1s-fert/ We figure the method will die out if/when most of us give up.

We play strong club vul, strong pass not. 13+ pass, openings are 7-12.
Thus the 1♠ fert is 0-6(7). It has scored well.
Good to preempt one major and bid the other.
(Also, if they double 16+ say, what is their negative?)


Anyway, our responses are simple after 1♠ - (nb) - ?

pass = up to 14-ish, a bit more with spade length
1NT = 15-18, maybe unbalanced, maybe a bit less with short spades
2♣ = 19+ unb
2♦/♥/♠ = overcall-style
2NT = 19-20

We can probably do better. The other day I picked up

♠KQTx ♥Axxxx ♦AKJx ♣---

2♥ and 1NT are ugly, though either would have worked well on the actual layout.

I'm thinking it's better to use 2m as Aspro (or Asptro), so
2♣ = hearts & another
2♦ = spades & a minor

Is that an improvement?
What elso might we try?

TIA]]> Thu, 11 Dec 2025 02:12:51 +0000 https://www.bridgebase.com/forums/topic/91459-responding-to-a-1s-fert/ https://www.bridgebase.com/forums/topic/91422-auby-ebenius-club/ Wed, 26 Nov 2025 09:21:35 +0000 https://www.bridgebase.com/forums/topic/91422-auby-ebenius-club/ https://www.bridgebase.com/forums/topic/91201-weak-preemptive-bids/ Sun, 07 Sep 2025 21:25:02 +0000 https://www.bridgebase.com/forums/topic/91201-weak-preemptive-bids/ https://www.bridgebase.com/forums/topic/91154-responses-to-1sp/ ♠ opening belong here or in "Natural Systems"?

Anyway:
1NT NF (OK SF, I should stop flogging that dead horse)
2♣ GF relay
2♦ 5+ hearts, primarily less-than-gf hands
2♥ 3+ support, (8?)9+ support points
2♠ 3+(usually just 3) support, 4-7(8) support points
Higher responses I am not sure about, but maybe something like
2NT invitational with one long minor (could throw some extreme gf hands in also)
3♣ weak (6-9 ish) both minors
higher bids are various distributional raises, maybe also a couple of bids for hands with very long hearts

So for example
1♠-2♦
2♥-pass (six-card hearts, less than invitational)

1♠-1NT
2m-2♥ (five hearts as a consequence of the above)

Has anyone tried something like this?]]> Mon, 25 Aug 2025 08:29:31 +0000 https://www.bridgebase.com/forums/topic/91154-responses-to-1sp/ https://www.bridgebase.com/forums/topic/91139-wj2020/
I like many aspects of the system, and it makes life easier to have a book we can just follow instead of writing out own system book.

But the 1♣ opening is heavier loaded than in other WJ versions.

For one thing, they open 1♣ with (31)45. The upside of this is that it allows responder to raise the 1♦ opening very aggressively. I wonder if it is worth the costs, though. It means that an auction like
1♣-1any
2♣
can be a 5-card suit and does not show extras.

And WJ2020 has Ekren 2♣ instead of Precision. So 1♣ also covers the hands that would normally open 2♣. Those hands, along with the 4♦5♣ minimums, rebid 2♣ (unless a fourcard major can be bid at the 1-level), pushing the 16+ hands with clubs further up the ladder.

I am not so far in the book that I have looked into how we resolve the 1♣ variants in contested auctions.

Anyone here having experience with this style?]]> Tue, 19 Aug 2025 07:28:49 +0000 https://www.bridgebase.com/forums/topic/91139-wj2020/ https://www.bridgebase.com/forums/topic/91049-minor-suit-forcing/ It is the key that both 1♣ and 1♦ openings are forcing bids. While 1♣ opening has a broad HCP range, 1♦ opening shows a hand with 15+ HCP and without 5 card major.
Besides 1♣ and 1♦ openings, all direct 2♣ and 2♦ responses, including those over 1♥ and 1♠ openings, with or without opponent interference are also forcing bids.

1 Opening Bids

1NT:
15-17 HCP, balanced or 5 card minor of 5332 shape

2NT:
21-22 HCP, balanced or 5 card minor of 5332 shape

2♣:
13-14 HCP, no 4 card major, no 5 card ♦, 5+ ♣ suit, not 5332 shape

2♦:
13-14 HCP, no 4 card major, 5+ ♦ suit, not 5332 shape

1♥:
11-14 HCP, 5+ ♥ suit, ♥ is longer than ♠ suit

1♠:
11-14 HCP, 5+ ♠ suit, ♠ is not shorter than ♥ suit

1♦:
18-20 HCP, balanced or 5 card minor of 5332 shape
23-24 HCP, balanced or 5 card minor of 5332 shape
15-17 HCP, no 4 card major, 5+ minor suit, not 5332 shape
18-24 HCP, no 5 card major, either 4441 shape or 5+ minor suit, not 5332 shape
25+ HCP, no 5 card major, 5+ minor suit

1♣:
11-12 HCP, 4 card major or 5+ minor suit including 5332 shape
13-14 HCP, 4 card major or balanced or 5 card minor of 5332 shape
15-17 HCP, 5+ major suit or 4 card major, either 5+ minor suit or 4441 shape
18+ HCP, 5+ major suit
25+ HCP, balanced or 4441 shape

All higher suit openings are weak and preemptive. The 3NT opening shows less than 15 HCP of a strong minor suit with 9 winners.

2 After 1NT, 2NT, 2♣, and 2♦ Openings

Stayman and Transfers are well-known responses to 1NT and 2NT openings and they are also adopted here.

The responses to 2♣ and 2♦ openings are simple and straightforward. Since the opener has no 4 card major, there is no need to seek for a 4-4 major match. Therefore

-2♥:
9+ HCP, 5+ ♥ suit, ♥ longer than ♠, asking for opener’s 3 ♥ card support

-2♠:
9+ HCP, 5+ ♠ suit, ♠ not shorter than ♥, asking for 3 ♠ card support

Additionally, the 2♣/2♦ opener only has a limited 13-14 HCP range, any other response is either game invitational or game sign-off.

3 After 1♥ and 1♠ Openings

In terms of responding to 1♥ and 1♠ openings, Minor Suit Forcing has two important differences from most other bidding systems such as Sayc, Two-Over-One, and Precision.

1) 1♠ response over 1♥ opening requires 5+ ♠ cards
2) 1NT is not forcing, while 2♣ and 2♦ responses are

Responses over 1♥ opening
-1♠:
9-11 HCP, no 3 ♥ cards, 5+ ♠ suit
12+ HCP, 5+ ♠ suit (may have 3+ ♥ cards)

-1NT:
9-11 HCP, no 5 ♠ cards, either no 2 ♥ cards or 2 ♥ without 4 ♠ cards

-2♣:
9-11 HCP, 2 ♥ with 4 ♠ cards
12+ HCP, no 3 ♥ cards, 4 ♠ cards

-2♦:
12+ HCP, no 3 ♥ cards, neither 4 ♠ cards

All other responses are more or less supporting the opening ♥ suit.

After 2♣ response:
--2♦: 11-13 HCP, 5+ ♥ suit, no 4 ♠ cards, forcing
--2♥: 14 HCP, 5+ ♥ suit, no 4 ♠ cards
--2♠: 11-13 HCP, 5+ ♥ suit with 4 ♠ cards
--2NT: 14 HCP, 5 ♥ suit with 4 ♠ cards
--3♥: 14 HCP, 6+ ♥ suit with 4 ♠ cards
--3♠: 11-12 HCP, 6+ ♥ suit with 5+ ♠ suit
--4♠: 13-14 HCP, 6+ ♥ suit with 5+ ♠ suit

After the opener's 2♦ rebid, responder's further bids
---2♥: 9-11 HCP, 2 ♥ cards, 4 ♠ cards
---2NT: 12-13 HCP, 2 ♥ cards, 4 ♠ cards, game invitation
---Rest bids are either forcing or game sign-off

After 2♦ response:
--2♥: 11-12 HCP, 6+ ♥ or 5 ♥ suit with two unstopped side suits
--2♠: 11-12 HCP, 5+ ♥ suit, 4+ ♠ suit
--2NT: 11-12 HCP, 5 ♥ suit with two stopped side suits
--3♣: 13-14 HCP, 5 ♥ suit, no 4 ♠ cards, 4+ ♣ suit
--3♦: 13-14 HCP, 5 ♥ suit, no 4 ♠ cards, 4+ ♦ suit
--3♥: 13-14 HCP, 6+ ♥ suit, no 4 ♠ cards
--3♠: 13-14 HCP, 5+ ♥ suit, 4+ ♠ suit
--3NT: 13-14 HCP, 5 ♥ suit of 5332 shape

Responses over 1♠ opening
-1NT:
9-11 HCP, no 2 ♠ cards or 2 ♠ without 4 ♥ cards
10-11 HCP, no 2 ♠ cards, 5+ ♥ suit

-2♣:
9-11 HCP, 2 ♠ with 4+ ♥ cards
12+ HCP, no 3 ♠ cards, 4 ♥ cards

-2♦:
12+ HCP, no 3 ♠ cards, neither 4 ♥ cards

-2♥:
12+ HCP, 5+ ♥ suit (may have 3+ ♠ cards)

All other responses are more or less supporting the opening ♠ suit.

After 2♣ response:
--2♦: 11-13 HCP, 5+ ♠ suit, no 4 ♥ cards, forcing
--2♥: 11-13 HCP, 5+ ♠ suit with 4+ ♥ cards
--2♠: 14 HCP, 5+ ♠ suit, no 4 ♥ cards
--2NT: 14 HCP, 5+ ♠ suit with 4 ♥ cards
--3♥: 14 HCP, 5 ♠ suit with 5 ♥ cards
--3♠: 11-12 HCP, 6+ ♠ suit with 5+ ♥ suit
--4♥: 13-14 HCP, 6+ ♠ suit with 5+ ♥ suit

After the opener's 2♦ rebid, responder's further bids
---2♥: 10-11 HCP, 2 ♠ cards, 5+ ♥ suit
---2♠: 9-11 HCP, 2 ♠ cards, 4 ♥ cards
---2NT: 12-13 HCP, 2 ♠ cards, 4 ♥ cards, game invitation
---Rest bids are either forcing or game sign-off

After 2♦ response:
--2♥: 11-12 HCP, 5+ ♠ suit, 4+ ♥ suit
--2♠: 11-12 HCP, 6+ ♠ suit or 5 ♠ suit with two unstopped side suits
--2NT: 11-12 HCP, 5 ♠ suit with two stopped side suits
--3♣: 13-14 HCP, 5 ♠ suit, no 4 ♥ cards, 4+ ♣ suit
--3♦: 13-14 HCP, 5 ♠ suit, no 4 ♥ cards, 4+ ♦ suit
--3♥: 13-14 HCP, 5+ ♠suit, 4+ ♥ suit
--3♠: 13-14 HCP, 6+ ♠ suit, no 4 ♥ cards
--3NT: 13-14 HCP, 5 ♠ suit of 5332 shape

4 Responses Over 1♣ and 1♦ Openings

For a given strong hand, the opener can choose one of two forcing openings 1♣ and 1♦ to start the bidding process.
As a result, the opener is able to describe the hand, almost in the first rebid, very precisely about the hand strength within 3 HCP range as well as the hand shape.

To describe the hand shape, we normally consider the following order
1) 5+ major suit
2) 4 card major, unbalanced (i.e. with 5+ minor suit or 4441 shape)
3) Balanced (i.e. 4333 or 4432 shape) with or without 4 card major
4) No 4 card major, 5 card minor of 5332 shape
5) No 4 card major, 5+ minor suit, not 5332 shape

For the first response of 1♣ and 1♦ openings, the responder has one of the following three things to do
1) Wait – a relatively weak hand waiting for the opener’s rebid
2) Show 5+ major – an average to strong hand willing to know the opener’s major support
3) Force a game – a strong hand enough to reach a game, although there is no 5 card major

Responses over 1♣ opening
-1♦ (wait):
0-8 HCP, any
9-12 HCP, no 5 card major

-1♥ (show 5+ ♥ suit):
9+ HCP, 5+ ♥ suit, ♥ longer than ♠

-1♠ (show 5+ ♠ suit):
9+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-1NT (force a game):
13+ HCP, balanced

-2♣ (force a game):
13+ HCP, no 5 card major, 5+ ♣ suit or 4 ♣, 4441 shape

-2♦ (force a game):
13+ HCP, no 5 card major, 5+ ♦ suit or 4 ♦, 1 ♣, 4441 shape

Responses over 1♦ opening
-1♥ (wait):
0-6 HCP, any
7-8 HCP, no 5 card major

-1♠ (show 5+ major):
7+ HCP, 5+ major suit (♥ and/or ♠)

-1NT (force a game):
9+ HCP, balanced or 5 card minor of 5332 shape

-2♣ (force a game):
9+ HCP, no 5 card major, 5+ ♣ suit or 4 ♣, 4441 shape

-2♦ (force a game):
9+ HCP, no 5 card major, 5+ ♦ suit or 4 ♦, 1 ♣, 4441 shape

It is to mention that no first response of 1♣ and 1♦ openings is higher than 2♦ bid and interestingly, all first responses except for 1♦ over 1♣ are also forcing bids.

5 After 1♣ Opening and 1♦ Response

The 1♦ response over 1♣ opening shows a weak hand with either 0-8 HCP, any shape or 9-12 HCP, no 5 card major.

Before rebid, the opener needs to analyze the hand strength and shape very carefully.
Any 1♣ opening hand can be categorized into one of the following 6 groups
1) 11-14 HCP, no 4 card major
2) 11-14 HCP, 4 card major or 15-17 HCP, 5+ major suit or 4441 shape
3) 18-20 HCP, 5+ major suit
4) 21+ HCP, 5+ major suit or 9+ winners
5) 25+ HCP, 4441 shape
6) 25+ HCP, balanced

The opener uses Pass and all possible bids from 1♥ up to 4♣ along with 4NT to describe the hand

Opener rebids – group 1
--Pass:
11-12 HCP, no 4 card major, 5+ ♦ suit

--2♣:
11-12 HCP, no 4 card major, 5+ ♣ suit

--1NT:
13-14 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape

The responder can further bid 2♥ or 2♠ to sign-off and bid 2NT to invite for 3NT.
There should be no direct jump to 3NT, unless the responder holds 11-12 HCP with a good minor suit.

Opener rebids – group 2
--1♥:
11-14 HCP, 4 ♥ cards
15-17 HCP, 5+ ♥ suit or 4 ♥ cards, unbalanced

--1♠:
11-14 HCP, 4 ♠ cards, no 4 ♥ cards
15-17 HCP, 5+ ♠ suit or 4 ♠ cards, unbalanced

As further responses, the responder should raise or jumped-raise the opener's major suit with 7+ HCP, 4+ major support.
The responder can also rebid 1♠ over opener’s 1♥ with 7-8 HCP, 4+ ♠ or 9-12 HCP, 4 ♠ cards.
Responder’s 1NT rebid shows 7-10 HCP without 4 major card support, while 2♣/2♦ rebids require 11-12 HCP, 4+ ♣/♦ cards without the major support.

The opener needs to rebid the same major in order to show 15-17 HCP, 5+ major suit.
If the opener further bids the other major as new suit, it means 15-17 HCP, 5+ old and 4+ new major suits.

Opener rebids – group 3
--2♥:
18-20 HCP, 5+ ♥ suit, ♥ longer than ♠

--2♠:
18-20 HCP, 5+ ♠ suit, ♠ not shorter than ♥

These two opener's jumped major suit bids are actually non-forcing.

Opener rebids – group 4
--3♥:
18-20 HCP, 6+ ♥ suit, 9 winners
21-22 HCP, 6+ ♥ suit or 5 ♥ suit, two unstopped side suits

--3♠:
18-20 HCP, 6+ ♠ suit, 9 winners
21-22 HCP, 6+ ♠ suit or 5 ♠ suit, two unstopped side suits

--4♥:
18-22 HCP, 7+ ♥ suit, 10 winners

--4♠:
18-22 HCP, 7+ ♠ suit, 10 winners

--2NT:
21-22 HCP, 5 card major, two stopped side suits

--3♣:
23+ HCP, 5+ major suit

Upon opener’s 2NT rebid, the responder can pass or bids 3♣ (2-3 HCP with 3+ major cards) or 3♦ (4+ HCP, game possible) waiting for opener's real major suit.
Upon opener's 3♣ rebid, the responder only returns 3♦ to let the opener further show the real major suit.

Opener rebids – group 5
--2♦:
25+ HCP, 4441 shape, forcing

The responder’s rebids are specifically designed as shown below
---2♥: no 4 ♥ cards
---2♠: 4+ ♥ cards, no 4 ♠ cards
---2NT: 4+ ♥ and 4+ ♠ cards

Opener’s further bids after responder’s 2♥:
----2♠: 4 ♠ cards, 4441 shape
----2NT: single ♠, 4441 shape

Opener’s further bids after responder’s 2♠:
----2NT: single ♥, 4441 shape
----3♥: 4 ♥ cards, 4441 shape, 4♥ invitation
----4♥: 4 ♥ cards, 4441 shape, sign-off

Opener’s further bids after responder’s 2NT:
----3♥: 4 ♥ cards, 4441 shape, 4♥ invitation
----3♠: 4 ♠ cards, 4441 shape, 4♠ invitation
----4♥: 4 ♥ cards, 4441 shape, sign-off
----4♠: 4 ♠ cards, 4441 shape, sign-off

Opener rebids – group 6
--3♦:
25-28 HCP, 4 card major, 4432 shape, forcing

The responder’s rebids are specifically designed as shown below
---3♥: no 4 ♥ cards
---3♠: 4+ ♥ cards, no 4 ♠ cards
---3NT: 4+ ♥ and 4+ ♠ cards

--3NT:
25-27 HCP, 4333 or no 4 card major, 4432 shape

--4♣:
28-30 HCP, balanced, direct asking for Ace

--4NT:
31+ HCP, balanced, direct asking for Ace

6 After 1♣ Opening and 1♥/1♠ Response

The direct 1♥/1♠ response over 1♣ opening shows that the responder holds 9+ HCP with 5+ ♥/♠ suit.

To rebid, the opener of course needs different methods comparing to the responder’s 1♦ response.
All possible opener’s rebids are divided into three groups as shown below
1) Direct major suit raise
2) Implied major suit support
3) Major suit denied or support postponed

Opener rebids – group 1
--Raise to 2♥/2♠:
11-13 HCP, counting the hand shape 11-13 points, 3 or 4 ♥/♠ support

--Raise to 3♥/3♠:
12-14 HCP, counting the hand shape 14-15 points, 3 or 4 ♥/♠ support

--Raise to 4♥/4♠:
13-14 HCP, counting the hand shape 16+ points, 3 or 4 ♥/♠ support

Opener rebids – group 2
--3♣:
15-17 HCP, 4 ♥/♠ support, single ♣, 4441 shape, forcing

--3♦:
15-17 HCP, 4 ♥/♠ support, single ♦, 4441 shape, forcing

--3♥ (after 1♠ response):
15-17 HCP, 4 ♠ support, single ♥, 4441 shape, forcing

--3♠ (after 1♥ response):
15-17 HCP, 4 ♥ support, single ♠, 4441 shape, forcing

--3NT:
15-17 HCP, 5+ ♥/♠ support, forcing

--4♣:
18-20 HCP, 5+ ♥/♠ support, direct asking for Roman keys
21+ HCP, 3+ ♥/♠ support

Opener rebids – group 3
--1♠ (after 1♥ response):
11-14 HCP, no 3 ♥ cards, 4 ♠ cards

--1NT (after 1♥ response):
13-14 HCP, no 3 ♥ cards, no 4 ♠ cards, either balanced or 5 minor of 5332 shape

--1NT (after 1♠ response):
11-12 HCP, no 3 ♠ cards, 4 ♥ cards
13-14 HCP, no 3 ♠ cards, either balanced or 5 minor of 5332 shape

--2♣:
11-12 HCP, no 3 ♥/♠ cards, no other 4 card major, 5+ ♣ suit

--2♦:
11-12 HCP, no 3 ♥/♠ cards, no other 4 card major, 5+ ♦ suit

--2♥ (after 1♠ response):
16-20 HCP, 5+ ♥ suit (may have 3+ ♠ support)
21+ HCP, 5+ ♥ suit, no 3 ♠ support

--2♠ (after 1♥ response):
15-20 HCP, 5+ ♠ suit (may have 3+ ♥ support)
21+ HCP, 5+ ♠ suit, no 3 ♥ support

--2NT:
15-17 HCP, single ♥/♠, 4441 shape
25+ HCP, no 3 ♥/♠ cards, balanced or single ♥/♠, 4441 shape

7 After 1♣ Opening and Game Forcing Response

After 1♣ opening, all three responses 1NT, 2♣, and 2♦ show the responder’s hand lack of 5 card major but strong enough to play a game.

Opener rebids after 1NT response
--2♣:
11-12 HCP, no 5 card major, 3+ ♣ cards (may have 4 card major)

--2♦:
11-12 HCP, no 5 card major, 3+ ♦ cards (may have 4 card major)

--2♥:
13-14 HCP, 4 ♥ cards, unbalanced
15-17 HCP, 5+ ♥ suit or 4 ♥ cards, unbalanced
25+ HCP, 4 ♥ cards, 4441 shape

--2♠:
13-14 HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced
15-17 HCP, 5+ ♠ suit or 4 ♠ cards, unbalanced
25+ HCP, 4 ♠ cards, single ♥, 4441 shape

--2NT:
13-14 HCP, balanced (may have 4 card major) or 5 minor suit of 5332 shape

--3♣:
25+ HCP, 4 ♣ cards, 4441 shape

--3♦:
25+ HCP, 4 ♦ cards, single ♣, 4441 shape

--3♥:
18+ HCP, 5+ ♥ suit, ♥ longer than ♠

--3♠:
18+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

--3NT (very unlikely):
25+ HCP, balanced, forcing

Opener rebids after 2♣ response
--2♦:
11-12 HCP, no 4 card major, 5+ ♦ suit

--3♣:
11-12 HCP, no 4 card major, 5+ ♣ suit
13-14 HCP, no 4 card major, 3+ ♣ cards, no major stopper

--2♥:
11-14 HCP, 4 ♥ cards
15-17 HCP, 5+ ♥ suit or 4 ♥ cards, unbalanced
25+ HCP, 4 ♥ cards, 4441 shape

--2♠:
11-14 HCP, 4 ♠ cards, no 4 ♥ cards
15-17, 5+ ♠ suit or 4 ♠ cards, unbalanced
25+, 4 ♠ cards, single ♥, 4441 shape

--2NT:
13-14 HCP, no 4 major cards, balanced or 5 minor suit of 5332 shape, with major stoppers

--3♥:
18+, HCP 5+ ♥ suit, ♥ longer than ♠

--3♠:
18+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

--3NT (very unlikely):
25+ HCP, balanced, forcing

Opener rebids after 2♦ response
--3♣:
11-12 HCP, no 4 card major, 5+ ♣ suit

--3♦:
11-12 HCP, no 4 card major, 5+ ♦ suit
13-14 HCP, no 4 card major, 3+ ♦ cards, no major stopper

--2♥:
11-14 HCP, 4 ♥ cards
15-17 HCP, 5+ ♥ suit or 4 ♥ cards, unbalanced
25+ HCP, 4 ♥ cards, 4441 shape

--2♠:
11-14 HCP, 4 ♠ cards, no 4 ♥ cards
15-17, 5+ ♠ suit or 4 ♠ cards, unbalanced
25+, 4 ♠ cards, single ♥, 4441 shape

--2NT:
13-14 HCP, no 4 major cards, balanced or 5 minor suit of 5332 shape, with major stoppers

--3♥:
18+, HCP 5+ ♥ suit, ♥ longer than ♠

--3♠:
18+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

--3NT (very unlikely):
25+ HCP, balanced, forcing

8 After 1♦ Opening and 1♥ Response

The 1♥ response over 1♦ opening shows a weak hand with either 0-6 HCP, any shape or 7-8 HCP, no 5 card major.

Before rebid, the opener needs to analyze the hand strength and shape very carefully.
Any 1♦ opening hand can be categorized into one of the following 6 groups
1) 18-20 or 22-23 HCP, balanced or 5+ minor suit of 5332 shape
2) 15-17 HCP, no 4 card major, 5+ minor suit, not 5332 shape
3) 18-20 HCP, no 5 card major, unbalanced or 21-22 HCP, 4441 shape or 23+ HCP, no 4 card major, 5+ minor suit
4) 21-22 HCP, no 4 card major, 5+ minor suit, not 5332 shape
5) 21-22 HCP, 4 card major, 5+ minor suit or 23-24 HCP, 4441 shape
6) 25+ HCP, 4 card major, 5+ minor suit

The opener uses all possible bids from 1♠ up to 4♦ along with 4NT, 5♣ and 5♦ to describe the hand

Opener rebids – group 1
--1NT:
18-20 HCP, balanced or 5 minor suit of 5332 shape

--2NT:
23-24 HCP, balanced or 5 minor suit of 5332 shape

The responder’s rebids are exactly the same as those responses used respectively to direct 1NT and 2NT openings.

Opener rebids – group 2
--2♣:
15-17 HCP, no 4 card major, 5+ ♣ suit, not 5332 shape

--2♦:
15-17 HCP, no 4 card major, 5+ ♦ suit, not 5332 shape

These two opener’s minor suit bids are basically discouraging.
However, the responder can bid 2♥/2♠ to show 7-8 HCP, 4 ♥/♠ cards looking for a 4-4 major match.
Holding 7-8 HCP, the responder can also bid 2NT with major stopper or raise the opener’s minor suit for 3NT try.

--3NT:
15-17, no 4 card major, 7+ minor suit, 9 winners

Opener rebids – group 3
--1♠:
18-20 HCP, no 5 card major, unbalanced
21-22 HCP, 4441 shape
23-24 HCP, no 4 card major, 5+ minor suit, not 5332 shape
25+ HCP, no 4 card major, 5+ minor suit

This opener’s rebid is virtual and forcing. The responder needs to rebid one of the following options
---1NT: 0-4 HCP, any shape
---2♣: 5-8 HCP, no 5 card major, 3+ ♣ cards (may have single 4 card major)
---2♦: 5-8 HCP, no 5 card major, 4+ ♦ cards (may have single 4 card major)
---2♥: 5-6 HCP, 5+ ♥ suit
---2♠: 5-6 HCP, 5+ ♠ suit
---2NT: 5-6 HCP, both 4 ♥ and 4 ♠ cards, 4432 or 4441 shape
---3♣: 7-8 HCP, no 4 card major, 5+ ♣ suit
---3♦: 7-8 HCP, no 4 card major, 5+ ♦ suit
---3NT: 7-8 HCP, both 4 ♥ and 4 ♠ cards, 4432 or 4441 shape

Upon the responder’s 1NT weak rebid, the opener’s further bids as shown below
----Pass:
18-20 HCP, 4441 shape

----2♣:
18-20 HCP, no 5 card major, 5+ ♣ suit, not 5332 shape

----2♦:
18-20 HCP, no 5 card major, 5+ ♦ suit, not 5332 shape

----2♥:
21-22 HCP, 4 ♥ cards, 4441 shape

----2♠:
21-22 HCP, 4 ♠ cards, single ♥, 4441 shape

----3♣:
23-24 HCP, no 4 card major, 5+ ♣ suit

----3♦:
23-24 HCP, no 4 card major, 5+ ♦ suit

----3NT:
25+ HCP, no 4 card major, 5+ minor suit

Opener rebids – group 4
--3♣:
21-22 HCP, no 4 card major, 5+ ♣ suit, not 5332 shape

--3♦:
21-22 HCP, no 4 card major, 5+ ♦ suit, not 5332 shape

Opener rebids – group 5
--2♥:
21-22 HCP, 4 ♥ cards, 5+ minor suit
23-24 HCP, 4 ♥ cards, 5+ minor suit or 4441 shape

--2♠:
21-22 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ minor suit
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ minor suit or 4441 shape

These two opener's major suit bids are actually non-forcing.
However, the responder can deny the major by bidding another suit or 2NT in order to find a different suit fit.

Opener rebids – group 6
--3♥:
25+ HCP, 4 ♥ cards, 5+ minor suit

--3♠:
25+ HCP, 4 ♠ cards, no 4 ♥ cards, 5+ minor suit

These two opener's major suit bids are game forcing.
The responder should raise if there is 4+ major card support or bid 3NT otherwise.

9 After 1♦ Opening and 1♠ Response

The 1♠ response over 1♦ opening shows that the responder holds at least one 5+ major suit.

Without knowing the real major, the opener keeps many rebids as used after 1♥ response while giving the responder a chance to further clarify.
--1NT:
18-20 HCP, balanced or 5 minor suit of 5332 shape
18-20 HCP, no 5 card major, unbalanced
21-22 HCP, 4441 shape

--2♣:
15-17 HCP, no 4 card major, 5+ ♣ suit, not 5332 shape

--2♦:
15-17 HCP, no 4 card major, 5+ ♦ suit, not 5332 shape

The responder further bids either 2♥ or 2♠ to tell the real 5+ major suit.
Then, the opener can raise (15-17 HCP) or jumped raise (18-22 HCP) the major, if there is 3+ major card support.
Otherwise, the opener simply bids anything else to deny the major support.

--2♥:
21-22 HCP, 4 ♥ cards, 5+ minor suit
23-24 HCP, 4 ♥ cards, 5+ minor suit or 4 ♥ cards, 4441 shape
25+ HCP, 4 ♥ cards, 5+ minor suit

--2♠:
21-22 HCP, 4 ♠ cards, no 4 ♥ cards, either 5+ minor suit or 4441 shape
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, either 5+ minor suit or 4441 shape
25+ HCP, 4 ♠ cards, no 4 ♥ cards, 5+ minor suit

--2NT:
23-24 HCP, balanced or 5 minor suit of 5332 shape

--3♣:
21+ HCP, no 4 card major, 5+ ♣ suit

--3♦:
21+ HCP, no 4 card major, 5+ ♦ suit

if the opener's 2♥/2♠ matches own major suit, the responder can start a slam try. Otherwise, the responder bids the new major suit.
Upon the opener’s 3NT/3♣/3♦ rebids, the responder simply bids either 3♥ or 3♠ to tell the real 5+ major suit.
Then, the opener can start a slam try if the major is supported or bid anything else to continue.

10 After 1♦ Opening and Game Forcing Response

After 1♦ opening, all three responses 1NT, 2♣, and 2♦ show the responder’s hand lack of 5 card major but strong enough to play a game.

Opener rebids after 1NT response
--2♣:
15-20 HCP, no 4 card major, 5+ ♣ suit, not 5332 shape

--2♦:
15-20 HCP, no 4 card major, 5+ ♦ suit, nor 5332 shape

--2♥:
18-22 HCP, 4 ♥ cards, unbalanced
23-24 HCP, 4 ♥ cards, balanced

--2♠:
18-22, 4 ♠ cards, no 4 ♥ cards, unbalanced
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, balanced

--2NT:
18-20 HCP, balanced (may have 4 card major) or 5 minor suit of 5332 shape

--3♣:
21+ HCP, no 4 card major, 5+ ♣ suit

--3♦:
21+ HCP, no 4 card major, 5+ ♦ suit

--3♥:
23-24 HCP, 4 ♥ cards, balanced
23+ HCP, 4 ♥ cards, unbalanced

--3♠:
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, balanced
23+ HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced

--3NT:
23-24 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape, non-forcing

Opener rebids after 2♣ response
--2♦:
15-20 HCP, no 4 card major, no 4 ♣ cards, 5+ ♦ suit

--3♣:
15-22 HCP, no 4 card major, 4+ ♣ cards, unbalanced

--3♦:
21+ HCP, no 4 card major, no 4 ♣ cards, 5+ ♦ suit

--2♥:
18-22 HCP, 4 ♥ cards, unbalanced
23-24 HCP, 4 ♥ cards, balanced

--2♠:
18-22 HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, balanced

--2NT:
18-20 HCP, balanced (may have 4 card major)

--3♥:
23+ HCP, 4 ♥ cards, unbalanced

--3♠:
23+ HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced

--3NT:
23-24 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape, non-forcing

--4♣:
23+ HCP, no 4 card major, 4+ ♣/♦ cards, direct asking for Roman keys

Opener rebids after 2♦ response
--3♣:
15+ HCP, no 4 card major, no 4 ♦ cards, 5+ ♣ suit

--3♦:
15-22 HCP, no 4 card major, 4+ ♦ cards, unbalanced

--2♥:
18-22 HCP, 4 ♥ cards, unbalanced
23-24 HCP, 4 ♥ cards, balanced

--2♠:
18-22 HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, balanced

--2NT:
18-20 HCP, balanced (may have 4 card major)

--3♥:
23+ HCP, 4 ♥ cards, unbalanced

--3♠:
23+ HCP, 4 ♠ cards, no 4 ♥ cards, unbalanced

--3NT:
23-24 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape, non-forcing

--4♣:
23+ HCP, no 4 card major, 4+ ♣/♦ cards, direct asking for Roman keys

11 Responses After 1♣ Opening and Opponent Interference

In Minor Suit Forcing bidding system, opponent interference does not introduce any burden to the responder.
Instead, the interference works as favorite because the responder can use Pass to show a real weak hand.

Without opponent interference, the responder has three bid options, i.e., Wait (1♦) Show Major (1♥/1♠) and Game Forcing (1NT/2♣/2♦).

Upon an opponent interference, the responder needs to adjust them accordingly.
1) Wait is split to Pass, 1NT, and Double/Redouble
2) Show Major continues to work
3) Game Forcing 2♣/2♦ still apply, while 1NT is replaced by 2NT and Cue Bid

Responses after opponent double
-Pass:
0-8 HCP, a weak hand

-1♦:
9-12 HCP, no 5 card major, 5+ ♦ suit

-1NT:
9-10 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape

-Redouble:
9-10 HCP, 4 card major or unbalanced
11-12 HCP, no 5 card major, any possible shape

-1♥:
9+ HCP, 5+ ♥ suit, ♥ longer than ♠

-1♠:
9+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2♣:
13+ HCP, no 5 card major, 4+ ♣ suit, unbalanced (may have 4 card major)

-2♦:
13+ HCP, no 5 card major, 4+ ♦ suit, unbalanced (may have 4 card major)

-2NT:
13+ HCP, balanced or 5 minor suit of 5332

Responses after opponent 1♦ overcall
-Pass:
0-8 HCP, a weak hand

-1NT:
9-10 HCP, no 4 card major, balanced with ♦ stoppers

-Double:
9-10 HCP, 4 card major or balanced without ♦ stopper or unbalanced
11-12 HCP, no 5 card major, any possible shape

-1♥:
9+ HCP, 5+ ♥ suit, ♥ longer than ♠

-1♠:
9+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2♣:
13+ HCP, no 5 card major, 4+ ♣ suit, unbalanced (may have 4 card major)

-2NT:
13+ HCP, no 4 card major, balanced with ♦ stoppers or 4+ ♦ cards

-2♦ (cue bid):
13+ HCP, 4 card major or balanced without ♦ stopper

Responses after opponent 1♥ overcall
-Pass:
0-8 HCP, a weak hand

-1NT:
9-10 HCP, no 4 ♠ cards, balanced with ♥ stoppers

-Double:
9-10 HCP, 4 ♠ cards or balanced without ♥ stopper or unbalanced
11-12 HCP, no 5 ♠ cards, any possible shape

-1♠:
9+ HCP, 5+ ♠ suit

-2♣:
13+ HCP, no 5 ♠ cards, 4+ ♣ suit, unbalanced (may have 4 ♠ cards)

-2♦:
13+ HCP, no 5 ♠ cards, 4+ ♦ suit, unbalanced (may have 4 ♠ cards)

-2NT:
13+ HCP, no 4 ♠ cards, balanced with ♥ stoppers or 4+ ♥ cards

-2♥ (cue bid):
13+ HCP, 4 ♠ cards or balanced without ♥ stopper

Responses after opponent 1♠ overcall
-Pass:
0-8 HCP, a weak hand

-1NT:
9-10 HCP, no 4 ♥ cards, balanced with ♠ stoppers

-Double:
9-10 HCP, 4+ ♥ suit or balanced without ♠ stopper or unbalanced
11-12 HCP, no 5 ♥ cards, any possible shape

-2♣:
13+ HCP, no 5 ♥ cards, 4+ ♣ suit, unbalanced (may have 4 ♥ cards)

-2♦:
13+ HCP, no 5 ♥ cards, 4+ ♦ suit, unbalanced (may have 4 ♥ cards)

-2♥:
11+ HCP, 5+ ♥ suit

-2NT:
13+ HCP, no 4 ♥ cards, balanced with ♠ stoppers or 4+ ♠ cards

-2♠ (cue bid):
13+ HCP, 4 ♥ cards or balanced without ♠ stopper

Responses after opponent 2♣ overcall
-Pass:
0-8 HCP, a weak hand
9-10 HCP, no 4 card major

-Double:
9-10 HCP, 4+ major suit
11-12 HCP, no 5 card major

-2♦:
13+ HCP, no 5 card major, 4+ ♦ suit, unbalanced (may have 4 card major)

-2♥:
11+ HCP, 5+ ♥ suit, ♥ longer than ♠

-2♠:
11+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2NT:
13+ HCP, no 4 card major, balanced with ♣ stoppers or 4+ ♣ cards

-3♣ (cue bid):
13+ HCP, 4 card major or balanced without ♣ stopper or unbalanced

Responses after opponent 2♦ overcall
-Pass:
0-8 HCP, a weak hand
9-10 HCP, no 4 card major

-Double:
9-10 HCP, 4+ major suit
11-12 HCP, no 5 card major

-2♥:
11+ HCP, 5+ ♥ suit, ♥ longer than ♠

-2♠:
11+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2NT:
13+ HCP, no 4 card major, balanced with ♦ stoppers or 4+ ♦ cards

-3♣:
13+ HCP, no 5 card major, 4+ ♣ suit, unbalanced (may have 4 card major)

-3♦ (cue bid):
13+ HCP, 4 card major or balanced without ♦ stopper

Responses after opponent 2♥ overcall
-Pass:
0-8 HCP, a weak hand
9-10 HCP, no 4 ♠ cards

-Double:
9-10 HCP, 4+ ♠ cards
11-12 HCP, no 5 ♠ cards

-2♠:
11+ HCP, 5+ ♠ suit

-2NT:
13+ HCP, no 4 ♠ cards, balanced with ♥ stoppers or 4+ ♥ cards

-3♣:
13+ HCP, no 5 ♠ cards, 4+ ♣ suit, unbalanced (may have 4 ♠ cards)

-3♦:
13+ HCP, no 5 ♠ cards, 4+ ♦ suit, unbalanced (may have 4 ♠ cards)

-3♥ (cue bid):
13+ HCP, 4 ♠ cards or balanced without ♥ stopper

Responses after opponent 2♠ overcall
-Pass:
0-8 HCP, a weak hand
9-10 HCP, no 4 ♥ cards

-Double:
9-10 HCP, 4+ ♥ cards
11-12 HCP, may have 4+ ♥ cards

-2NT:
13+ HCP, no 4 ♥ cards, balanced with ♠ stoppers or 4+ ♠ cards

-3♣:
13+ HCP, no 5 ♥ cards, 4+ ♣ suit, unbalanced (may have 4 ♥ cards)

-3♦:
13+ HCP, no 5 ♥ cards, 4+ ♦ suit, unbalanced (may have 4 ♥ cards)

-3♥:
13+ HCP, 5+ ♥ suit

-3♠ (cue bid):
13+ HCP, 4 ♥ cards or balanced without ♠ stopper

12 Opener Rebids After Opponent Interference With 1♣ Opening

Now we turn to the 1♣ opener and present details about how opponent interference is handled.

Opener rebids after opponent double

This case happens when LHO doubled and the responder passed.
--1♦:
11-12 HCP, no 4 card major, 5+ ♦ suit

--1♥:
11-12 HCP, 4 ♥ cards, 5+ minor suit
13-14 HCP, 4 ♥ cards
15-17 HCP, 5+ ♥ suit

--1♠:
11-12 HCP, 4 ♠ cards, 5+ minor suit
13-14 HCP, 4 ♠ cards, no 4 ♥ cards
15-17 HCP, 5+ ♠ suit

--1NT:
13-14 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape

--2♣:
11-12 HCP, no 4 card major, 6+ ♣ suit

--2♦:
11-12 HCP, no 4 card major, 6+ ♦ suit

--2♥:
18-20 HCP, 5+ ♥ suit, ♥ longer than ♠

--2♠:
18-20 HCP, 5+ ♠ suit, ♠ not shorter than ♥

--2NT:
25+ HCP, single ♥/♠, 4441 shape

--3♣:
25+ HCP, single ♣, 4441 shape

--3♦:
25+ HCP, single ♦, 4441 shape

--Redouble:
15-17 HCP, 4441 shape
18+ HCP, 5+ major suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♥/3♠, and 4♥/4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 1♦ overcall

This case happens when LHO bid 1♦ and the responder passed.
--1♥:
11-12 HCP, 4 ♥ cards, 5+ ♣ suit
13-14 HCP, 4 ♥ cards
15-17 HCP, 5+ ♥ suit

--1♠:
11-12 HCP, 4 ♠ cards, 5+ ♣ suit
13-14 HCP, 4 ♠ cards, no 4 ♥ cards
15-17 HCP, 5+ ♠ suit

--1NT:
13-14 HCP, no 4 card major, balanced with ♦ stoppers

--2♣:
11-12 HCP, no 4 card major, 6+ ♣ suit
13-14 HCP, 5 ♣ suit of 5332 shape

--2♥:
18-20 HCP, 5+ ♥ suit, ♥ longer than ♠

--2♠:
18-20 HCP, 5+ ♠ suit, ♠ not shorter than ♥

--2♦:
25+ HCP, single ♦, 4441 shape

--2NT:
25+ HCP, 4 ♦ cards, 4441 shape

--Double:
15-17 HCP, 4441 shape
18+ HCP, 5+ major suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♥/3♠, and 4♥/4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 1♥ overcall

This case happens when LHO bid 1♥ and the partner passed or the partner responded with 1♦ and RHO made 1♥ overcall.
--1♠:
11-12 HCP, 4 ♠ cards, 5+ minor suit
13-14 HCP, 4 ♠ cards
15-17 HCP, 5+ ♠ suit

--1NT:
13-14 HCP, no 4 ♠ cards, 4 ♥ cards or balanced with ♥ stoppers

--2♣:
11-12 HCP, no 4 ♠ cards, 6+ ♣ suit
13-14 HCP, 5 ♣ suit of 5332 shape

--2♦:
11-12 HCP, no 4 ♠ cards, 6+ ♦ suit
13-14 HCP, 5 ♦ suit of 5332 shape

--2♠:
18-20 HCP, 5+ ♠ suit

--2♥:
25+ HCP, single ♥, 4441 shape

--2NT:
25+ HCP, 4 ♥ cards, 4441 shape

--Double:
15-17 HCP, 4 ♠ cards, 4441 shape
18+ HCP, 5+ ♠ suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♠, and 4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 1♠ overcall

This case happens when LHO bid 1♠ and the partner passed or the partner responded with 1♦ and RHO made 1♠ overcall.
--1NT:
13-14 HCP, 4 ♠ cards or balanced with ♠ stoppers

--2♣:
11-12 HCP, 6+ ♣ suit
13-14 HCP, 4 ♥ cards, 5+ ♣ suit or 5 ♣ suit of 5332 shape

--2♦:
11-12 HCP, 6+ ♦ suit
13-14 HCP, 4 ♥ cards, 5+ ♦ suit or 5 ♦ suit of 5332 shape

--2♥:
15-17 HCP, 5+ ♥ suit

--2♠:
25+ HCP, single ♠, 4441 shape

--2NT:
25+ HCP, 4 ♠ cards, 4441 shape

--Double:
13-14 HCP, single ♠, 4441 shape
15-17 HCP, 4 ♥ cards, 4441 shape
18+ HCP, 5+ ♥ suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♥ and 4♥ are the same as those after 1 ♦ response.

Opener rebids after opponent 2♣ overcall

This case happens when LHO bid 2♣ and the partner passed or the partner responded with 1♦ and RHO made 2♣ overcall.
--2♦:
11-12 HCP, 6+ ♦ suit
13-14 HCP, 4 card major, 5+ ♦ suit or 5 ♦ suit of 5332 shape

--2♥:
15-17 HCP, 5+ ♥ suit, ♥ longer than ♠

--2♠:
15-17 HCP, 5+ ♠ suit, ♠ not shorter than ♥

--2NT:
25+ HCP, 4 ♣ cards, 4441 shape

--3♣:
25+ HCP, single ♣, 4441 shape

--Double:
13-14 HCP, single ♣, 4441 shape
15-17 HCP, 4 ♠ cards, 4 ♥ cards, 4441 shape
18+ HCP, 5+ major suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♥/3♠ and 4♥/4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 2♦ overcall

This case happens when LHO bid 2♦ and the partner passed or the partner responded with 1♦ and RHO made 2♦ overcall.
--3♣:
13-14 HCP, 4 card major, 6+ ♣ suit

--2♥:
15-17 HCP, 5+ ♥ suit, ♥ longer than ♠

--2♠:
15-17 HCP, 5+ ♠ suit, ♠ not shorter than ♥

--2NT:
25+ HCP, 4 ♦ cards, 4441 shape

--3♦:
26+ HCP, single ♦, 4441 shape

--Double:
13-14 HCP, single ♦, 4441 shape or 4 card major, 5 ♣ suit
15-17 HCP, 4 ♠ cards, 4 ♥ cards, 4441 shape
18+ HCP, 5+ major suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♥/3♠, and 4♥/4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 2♥ overcall

This case happens when LHO bid 2♥ and the partner passed or the partner responded with 1♦ and RHO made 2♥ overcall.
--3♣:
13-14 HCP, 4 ♠ cards, 6+ ♣ suit

--3♦:
13-14 HCP, 4 ♠ cards, 6+ ♦ suit

--2♠:
16-17 HCP, 5+ ♠ suit

--2NT:
25+ HCP, 4 ♥ cards, 4441 shape

--3♥:
26+ HCP, single ♥, 4441 shape

--Double:
13-14 HCP, single ♥, 4441 shape or 4 ♠ cards, 5 minor suit
15-17 HCP, 4 ♠ cards, 4441 shape
18+ HCP, 5+ ♠ suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♠, and 4♠ are the same as those after 1 ♦ response.

Opener rebids after opponent 2♠ overcall

This case happens when LHO bid 2♠ and the partner passed or the partner responded with 1♦ and RHO made 2♠ overcall.
--3♣:
13-14 HCP, 4 ♥ cards, 6+ ♣ suit

--3♦:
13-14 HCP, 4 ♥ cards, 6+ ♦ suit

--3♥:
15-17 HCP, 5+ ♥ suit

--2NT:
25+ HCP, 4 ♠ cards, 4441 shape

--3♠:
26+ HCP, single ♠, 4441 shape

--Double:
13-14 HCP, single ♠, 4441 shape or 4 ♥ cards, 5 minor suit
15-17 HCP, 4 ♥ cards, 4441 shape
18+ HCP, 5+ ♥ suit, no 9 winners
25+ HCP, balanced

The major suit bids 3♠, and 4♠ are the same as those after 1 ♦ response.

13 Responses After 1♦ Opening and Opponent Interference

Without opponent interference, the responder has three bid options, i.e., Wait (1♥) Show Major (1♠) and Game Forcing (1NT/2♣/2♦).

Upon an opponent interference, the responder needs to adjust them accordingly.
1) Wait is split to Pass, 1NT/non-jumped 2NT, and Double/Redouble
2) Show Major bid is separated to two bids making clear about the real major
3) Game Forcing 2♣/2♦ still apply, while 1NT is replaced by jumped-NT and Cue Bid

Responses after opponent double
-Pass:
0-6 HCP, a weak hand

-1NT:
7-8 HCP, no 4 card major, balanced or 5 minor suit of 5332 shape

-Redouble:
7-8 HCP, 4 card major or unbalanced

-1♥:
7+ HCP, 5+ ♥ suit, ♥ longer than ♠

-1♠:
7+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2♣:
9+ HCP, no 5 card major, 4+ ♣ suit, unbalanced (may have 4 card major)

-2♦:
9+ HCP, no 5 card major, 4+ ♦ suit, unbalanced (may have 4 card major)

-2NT:
9+ HCP, balanced or 5 minor suit of 5332 shape

Responses after opponent 1♥ overcall
-Pass:
0-6 HCP, a weak hand

-1NT:
7-8 HCP, no 4 ♠ cards, balanced with ♥ stoppers

-Double:
7-8 HCP, 4 ♠ cards or balanced without ♥ stopper or unbalanced

-1♠:
7+ HCP, 5+ ♠ suit

-2♣:
9+ HCP, no 5 ♠ cards, 4+ ♣ suit, unbalanced (may have 4 ♠ cards)

-2♦:
9+ HCP, no 5 ♠ cards, 4+ ♦ suit, unbalanced (may have 4 ♠ cards)

-2♥ (cue bid):
9+ HCP, 4 ♠ cards or balanced without ♥ stopper

-2NT:
9+ HCP, no 4 ♠ cards, balanced with ♥ stoppers

Responses after opponent 1♠ overcall
-Pass:
0-6 HCP, a weak hand

-1NT:
7-8 HCP, no 4 ♥ cards, balanced with ♠ stoppers

-Double:
7-8 HCP, 4 ♥ cards or balanced without ♠ stopper or unbalanced

-2♣:
9+ HCP, no 5 ♥ cards, 4+ ♣ suit, unbalanced (may have 4 ♥ cards)

-2♦:
9+ HCP, no 5 ♥ cards, 4+ ♦ suit, unbalanced (may have 4 ♥ cards)

-2♥:
7+ HCP, 5+ ♥ suit

-2♠ (cue bid):
9+ HCP, 4 ♥ cards or balanced without ♠ stopper

-2NT:
9+ HCP, no 4 ♥ cards, balanced with ♠ stoppers

Responses after opponent 2♣ overcall
-Pass:
0-6 HCP, a weak hand

-Double:
7-8 HCP, 4 card major or balanced without ♣ stopper or unbalanced

-2♦:
9+ HCP, no 5 card major, 4+ ♦ suit, unbalanced (may have 4 card major)

-2♥:
7+ HCP, 5+ ♥ suit, ♥ longer than ♠

-2♠:
7+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2NT:
7-8 HCP, no 4 card major, balanced with ♣ stoppers

-3♣ (cue bid):
9+ HCP, 4 card major or balanced without ♣ stopper

-3NT:
9+ HCP, no 4 card major or balanced with ♣ stoppers

Responses after opponent 2♦ overcall
-Pass:
0-6 HCP, a weak hand

-Double:
7-8 HCP, 4 card major or balanced without ♦ stopper or unbalanced

-2♥:
7+ HCP, 5+ ♥ suit, ♥ longer than ♠

-2♠:
7+ HCP, 5+ ♠ suit, ♠ not shorter than ♥

-2NT:
7-8 HCP, no 4 card major, balanced with ♦ stoppers

-3♣:
9+ HCP, no 5 ♥ cards, 4+ ♣ suit, unbalanced (may have 4 card major)

-3♦ (cue bid):
9+ HCP, 4 card major or balanced without ♦ stopper

-3NT:
9+ HCP, no 4 card major, balanced with ♦ stoppers

Responses after opponent 2♥ overcall
-Pass:
0-6 HCP, a weak hand

-Double:
7-8 HCP, 4 ♠ cards or balanced without ♥ stopper or unbalanced

-2♠:
7+ HCP, 5+ ♠ suit

-2NT:
7-8 HCP, no 4 ♠ cards, balanced with ♥ stoppers

-3♣:
9+ HCP, no 5 ♠ cards, 4+ ♣ suit, unbalanced (may have 4 ♠ cards)

-3♦:
9+ HCP, no 5 ♠ cards, 4+ ♦ suit, unbalanced (may have 4 ♠ cards)

-3♥ (cue bid):
9+ HCP, 4 ♠ cards or balanced without ♥ stopper or unbalanced

-3NT:
9+ HCP, no 4 ♠ cards, balanced with ♥ stoppers

Responses after opponent 2♠ overcall
-Pass:
0-6 HCP, a weak hand

-Double:
7-8 HCP, 4+ ♥ cards or balanced without ♠ stopper or unbalanced

-2NT:
7-8 HCP, no 4 ♠ cards, balanced with ♠ stoppers

-3♣:
9+ HCP, no 5 ♥ cards, 4+ ♣ suit, unbalanced (may have 4 ♥ cards)

-3♦:
9+ HCP, no 5 ♥ cards, 4+ ♦ suit, unbalanced (may have 4 ♥ cards)

-3♥:
9+ HCP, 5+ ♥ suit

-3♠ (cue bid):
9+ HCP, 4 ♥ cards or balanced without ♠ stopper

-3NT:
9+ HCP, no 4 ♥ cards, balanced without ♠ stopper

14 Opener Rebids After Opponent Interference With 1♦ Opening

Now we turn to the 1♦ opener and present details about how opponent interference is handled.

Opener rebids after opponent double

This case happens when LHO bid doubled and the responder passed.
--1♥:
15-17 HCP, 4 ♥ cards, 5+ minor suit
18-20 HCP, 4 ♥ cards, 5+ minor suit or 4 ♥ cards, 4441 shape

--1♠:
15-17 HCP, 4 ♠ cards, 5+ minor suit
18-20 HCP, 4 ♠ cards, 5+ minor suit or 4 ♠ cards, single ♥, 4441 shape

--2♣:
15-20 HCP, no 4 card major, 5+ ♣ suit

--2♦:
15-20 HCP, no 4 card major, 5+ ♦ suit

--Redouble:
21-22 HCP, 4441 shape
23-24 HCP, no 4 card major, 5+ minor suit, not 5332 shape
25+ HCP, no 4 card major, 5+ minor suit

All other opener's bids including 1NT/2NT, 2♥/2♠, 3♣/3♦, and 3♥/3♠ are the same as those after responder's 1 ♥ response.

Opener rebids after opponent 1♥ overcall

This case happens when LHO bid 1♥ and the responder passed.
--1♠:
15-20 HCP, 4 ♠ cards, 5+ minor suit or 4 ♠ cards, 4441 shape

--1NT:
18-20 HCP, balanced with ♥ stoppers

--2♣:
15-20 HCP, no 4 ♠ cards, 5+ ♣ suit

--2♦:
15-20 HCP, no 4 ♠ cards, 5+ ♦ suit

--2♠:
21-22 HCP, 4 ♠ cards, 5+ minor suit
23-24 HCP, 4 ♠ cards, 5+ minor suit or 4 ♠ cards, 4441 shape

--3♣:
21-22 HCP, no 4 ♠ cards, 5+ ♣ suit

--3♦:
21-22 HCP, no 4 ♠ cards, 5+ ♦ suit

--2♥:
23-24 HCP, single ♥, 4441 shape

--2NT:
23-24 HCP, 4 ♥ cards or ♥ stoppers

--3♠:
25+ HCP, 4 ♠ cards, 5+ minor suit

--Double:
21-22 HCP, 4 ♠ cards, 4441 shape
23-24 HCP, no 4 ♠ cards, 5+ minor suit, not 5332 shape
25+ HCP, no 4 ♠ cards, 5+ minor suit

Opener rebids after opponent 1♠ overcall

This case happens when LHO bid 1♠ and the partner passed or the partner responded with 1♥ and RHO made 1♠ overcall.
--1NT:
18-20 HCP, balanced with ♠ stoppers

--2♣:
15-17 HCP, 5+ ♣ suit (may have 4 ♥ cards)
18-20 HCP, no 4 ♥ cards, 5+ ♣ suit

--2♦:
15-17 HCP, 5+ ♦ suit (may have 4 ♥ cards)
18-20 HCP, no 4 ♥ cards, 5+ ♦ suit

--2♥:
21-22 HCP, 4 ♥ cards, 5+ minor suit
23-24 HCP, 4 ♥ cards, 5+ minor suit or 4 ♥ cards, 4441 shape

--3♣:
21-22 HCP, no 4 ♥ cards, 5+ ♣ suit

--3♦:
21-22 HCP, no 4 ♥ cards, 5+ ♦ suit

--2♠:
23-24 HCP, single ♠, 4441 shape

--2NT:
23-24 HCP, 4 ♠ cards or ♠ stoppers

--3♥:
25+ HCP, 4 ♥ cards, 5+ minor suit

--Double:
18-20 HCP, 4 ♥ cards, 5+ minor suit or single ♠, 4441 shape
21-22 HCP, 4 ♥ cards, 4441 shape
23-24 HCP, no 4 ♥ cards, 5+ minor suit, not 5332 shape
25+ HCP, no 4 ♥ cards, 5+ minor suit

Opener rebids after opponent 2♣ overcall

This case happens when LHO bid 2♣ and the partner passed or the partner responded with 1♥ and RHO made 2♣ overcall.
--2♦:
15-17 HCP, 5+ ♦ suit (may have 4 card major)
18-20 HCP, no 4 card major, 5+ ♦ suit

--2♥:
21-22 HCP, 4 ♥ cards, 5+ ♦ suit
23-24 HCP, 4 ♥ cards, 5+ ♦ suit or 4 ♥ cards, 4441 shape

--2♠:
21-22 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ ♦ suit
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ ♦ suit or 4 ♠ cards, no 4 ♥ cards, 4441 shape

--3♦:
21-22 HCP, no 4 card major, 5+ ♦ suit

--2NT:
23-24 HCP, 4 ♣ cards or ♣ stoppers

--3♣:
23-24 HCP, single ♣, 4441 shape

--3♥:
25+ HCP, 4 ♥ cards, 5+ minor suit

--3♠:
25+ HCP, 4 ♠ cards, 5+ minor suit

--Double:
18-20 HCP, 4 card major, 5+ ♦ or single ♣, 4441 shape
21-22 HCP, 4 ♠ cards, 4 ♥ cards, 4441 shape
23-24 HCP, no 4 card major, 5+ ♦ suit, not 5332 shape
25+ HCP, no 4 card major, 5+ ♦ suit

Opener rebids after opponent 2♦ overcall

This case happens when LHO bid 2♦ and the partner passed or the partner responded with 1♥ and RHO made 2♦ overcall.
--2♥:
21-22 HCP, 4 ♥ cards, 5+ ♣ suit
23-24 HCP, 4 ♥ cards, 5+ ♣ suit or 4 ♥ cards, 4441 shape

--2♠:
21-22 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ ♣ suit
23-24 HCP, 4 ♠ cards, no 4 ♥ cards, 5+ ♣ suit or 4 ♠ cards, ♥, single 4441 shape

--3♣:
18-20 HCP, no 4 card major, 6+ ♣ suit
21-22 HCP, no 4 card major, 5+ ♣ suit

--2NT:
23-24 HCP, 4 ♦ cards or ♦ stoppers

--3♦:
23-24 HCP, single ♦, 4441 shape

--3♥:
25+ HCP, 4 ♥ cards, 5+ minor suit

--3♠:
25+ HCP, 4 ♠ cards, 5+ minor suit

--Double:
18-20 HCP, 4 card major, 5+ ♣ suit or single ♦, 4441 shape
21-22 HCP, 4 ♠ cards, 4 ♥ cards, 4441 shape
23-24 HCP, no 4 card major, 5+ ♣ suit, not 5332 shape
25+ HCP, no 4 card major, 5+ ♣ suit

Opener rebids after opponent 2♥ overcall

This case happens when LHO bid 2♥ and the partner passed or the partner responded with 1♥ and RHO made 2♥ overcall.
--2♠:
21-22 HCP, 4 ♠ cards, 5+ ♣ suit
23-24 HCP, 4 ♠ cards, 5+ ♣ suit or 4 ♠ cards, 4441 shape

--3♣:
18-20 HCP, no 4 ♠ cards, 6+ ♣ suit
21-22 HCP, no 4 ♠ cards, 5+ ♣ suit

--3♦:
18-20 HCP, no 4 ♠ cards, 6+ ♦ suit
21-22 HCP, no 4 ♠ cards, 5+ ♦ suit

--2NT:
23-24 HCP, 4 ♥ cards or ♥ stoppers

--3♥:
23-24 HCP, single ♥, 4441 shape

--3♠:
25+ HCP, 4 ♠ cards, 5+ minor suit

--Double:
18-20 HCP, 4 ♠ cards, 5+ ♣ suit or single ♥, 4441 shape
21-22 HCP, 4 ♠ cards, 4441 shape
23-24 HCP, no 4 ♠ cards, 5+ minor suit, not 5332 shape
25+ HCP, no 4 ♠ cards, 5+ minor suit

Opener rebids after opponent 2♠ overcall

This case happens when LHO bid 2♠ and the partner passed or the partner responded with 1♥ and RHO made 2♠ overcall.
--3♣:
18-20 HCP, no 4 ♥ cards, 6+ ♣ suit
21-22 HCP, no 4 ♥ cards, 5+ ♣ suit

--3♦:
18-20 HCP, no 4 ♥ cards, 6+ ♦ suit
21-22 HCP, no 4 ♥ cards, 5+ ♦ suit

--3♥:
23-24 HCP, 4 ♥ cards, 5+ minor suit or 4 ♥ cards, 4441 shape

--2NT:
23-24 HCP, 4 ♠ cards or ♠ stoppers

--3♠:
23-24 HCP, single ♠, 4441 shape

--Double:
18-20 HCP, single ♠, 4441 shape
21-22 HCP, 4 ♥ cards, 5+ minor suit or 4 ♥ cards, 4441 shape
23-24 HCP, no 4 ♥ cards, 5+ minor suit, not 5332 shape
25+ HCP, 5+ minor suit]]> Thu, 24 Jul 2025 19:39:59 +0000 https://www.bridgebase.com/forums/topic/91049-minor-suit-forcing/ https://www.bridgebase.com/forums/topic/91040-strong-3-suited-hand/ What do you do with a 4441 hand with 8+ HCP when partner opens a precision 1C ? Parner and I jump to one below the shortness if 8-14, but are there better options ? Mon, 21 Jul 2025 10:50:58 +0000 https://www.bridgebase.com/forums/topic/91040-strong-3-suited-hand/ https://www.bridgebase.com/forums/topic/90986-to-transfer-or-not/
Appreciate any responses. Would it matter if your Major is spades vs hearts is a tangential question]]> Sat, 05 Jul 2025 14:11:37 +0000 https://www.bridgebase.com/forums/topic/90986-to-transfer-or-not/ https://www.bridgebase.com/forums/topic/90766-options-for-1m-unbalanced-2c-invite/ unless 4M441). A 2♣ response shows a hand with less 3-card support that's least invitational but can't necessarily GF. It seems that there are several options for opener's rebid over the 2♣ response.

• 2♣ as optional relay to 2♦
  ........2♦: Waiting response with non-min hands
  ................2M: 2-card support, etc.
  ........2x: Min hands
  ........2N: 4441M?
  ........3m: ??
  
• 2♣
  ........2♦: Waiting response; may be GF with 6+M or min 4M441
  ...................2M: 2-card support
  ........2OM: Natural, F1
  ........2N: Max, 4M441
  ........3x: GF showing 5-4/5-5m

.
Any other suggestions? Note that invitational hands with 4+♠ might be an interesting corner case over 1♥.]]> Sat, 26 Apr 2025 15:42:29 +0000 https://www.bridgebase.com/forums/topic/90766-options-for-1m-unbalanced-2c-invite/ https://www.bridgebase.com/forums/topic/90765-imprecision-1d-2n-as-bal-gf-or-weak-3m/ ♦ - 2N as either 13-16 balanced GF (asking for shortness) OR weak 3m.

• How does this mesh with the new ACBL charts?
  
• What type of hands would make this response (as opposed to responding 2m, which is also forcing)? Also, is the intent to be able to stop in 4m opposite shortness and no stopper?

]]> Sat, 26 Apr 2025 15:13:06 +0000 https://www.bridgebase.com/forums/topic/90765-imprecision-1d-2n-as-bal-gf-or-weak-3m/