1♦ Opening bid & Responses

♣ ♥ ♠ ♦

Requirements:

A 1♦ opening categorically denies any 5+ card Major or 4-4 in the Majors.
A 1♦ opening requires a 5+ card Diamond suit and ideally 12+ HCP. However 10+ is acceptable as long as a rebid is available such as a rebiddable 6+ card Diamond suit or a second suit of 4 cards.
The following are other BETA openings that always take preference:

2NT     21-22 Balanced - ♦ 's may be 5 cards in a balanced hand
2♣ 23+ Balanced OR 5+ ♦'s & <= 3 1/2 LTC
2♦     19-20 Balanced OR 5+-5+ in ♦ & ♠ <=7LTC
3♣    5+-5+ in ♦ & ♥ <=7LTC

Important special sequences:

A hand with a 5+ cards in both minors with a maximum of 7LTC♦ opening is opened 1♦ and rebid with a 3♣ NF rebid whether with a jump or NOT.
This mirrors the sequence of a 1♠ opening where a rebid of 3♣ also announces a 5-5 or better ♠ & ♣---. BUT a jump rebid in any other other suit shows 15+ , a single suited hand & good honour control in the short suit (normally 2-3 cards). Note a 1H opening and a 3♣ rebid is NOT showing a 5-5 but a shortage 2-3 cards & 15+ HCP.
Otherwise any non-jump bid in BETA in any hitherto unbid suit is to be considered as a 1 round force.

[Note: Beware 1♦ and a JUMP rebid in any suit other than Clubs is NOT at all the same - it shows a 15+ single suited hand with good control in a SHORT suit (1)-3 cards and is Forcing - essentially is a cue-bid.

Partner's Responses 1♦ - ?

It is important to note that there is essentially a close synergy between 1♣ & 1♦ sequences in Beta.
In both cases we give priority to showing a 4+ card Major regardless of any other suit or even NT's
Therefore the sequences 1♣-1♦(4+hearts) & 1♦-1♥(4+ Hearts) are synonomous and similarly 1♣-1♥(4+spades) & 1♦-1♠(4+ Spades) which categorically denies a 4+ Heart suit as does 1♣-1♥. These 1♦-1Ma sequences always take preference over bidding 1♦-2♣ (10+HCP & 5+ Clubs) or 1♦-2♦ (inverted minor sequence requires 10+ HCP & 4+ card support) & 1♦-3♦|3♣ are weak <= 9HCP. 3♦ pre-emptive response shows 4+ diamonds and 5+ Diamonds. The sequence: 1♦-3♣ is a Break-out - usually a STOP bid requiring 6+ clubs.
Finally 1♦ followed by a 3♣ rebid shows , <=7 LTC and at least 5-5 in minors.

The similarlity does not end there, if you hold both major 4+ cards responder must show the Hearts first regardless of their respective quality or lengths. Beta can handle this largely as the concept of reverse is not used in BETA. Responder must show 4+ card Major response directly (with both Majors the initial response MUST be 1♥, 2♥ if 15+ as in 1♣ sequences.
A 1N rebid by opener shows 12-16 strictly & 2N with jump 17-18 always balanced & no singleton. Responder has a mandatory 2♣ response showing with 9+HCP. This also mirrors 1♣ sequences.

Important Sequences:-

1♦-1NTClassic 5-9HCP BUT also denies any 4 card Major categorically
1♦-1♥-2♥ shows 4 card support.
1♦-1♥-1♠ with a 4 card Spade & denying a 4 card Heart support - as responder may be 4-4 in the Majors.
1♦-1♠-2♥|2♣ are simply forcing bids with a 2nd suit natural 4+ card Heart or Club suit.
1♦-1any-1N Shows 12-16 CROWHURST & denies 4 card fit with partner. Partner must continue 2♣ with 9+HCP.
1♦-1any-2N Shows 17-18 HCP.
1♦-2♣-2N shows 12-14

3 Universal facts in BETA:-
Break-outs - direct responses in a new suit at the 3-level over partners opening bid:
1♦-3♣|♥ |♠
Opener's rebid of his suit promises 6+ cards - same for hearts and spade rebids - not showing more strength than opening values.
1♦-any-2♦ Opener's rebid shows 6+ cards & if 'any' is a Major then 2D rebid denies support for the Major
1♦-1♠-2|♠ Shows a 4-4 spade fit (identical for Hearts).

However responder's rebid of a suit also shows 6+ cards BUT also shows weakness <=9HCP and is technically a STOP bid.
E,g. 1♦-2♣-2N-3♣
Note: 1♦-1Ma(opp)-* Shows the other Major & 1♦-*(opp)-** Shows both Majors - a further similarity to 1♣ sequences.

Regular responses to a 1♦ opening:

PASS: 0-4(5) HCP

1Ma: 4+ Cards - with both bid 1♥ always

2♣: 10+ 4+ card suit. MAY NOT HIDE a 4+ card Major
1N: Shows limited values (5)-9 HCP- denies 4 card support & denies a Major

2NT BARON: Balanced. Only without intervention. Shows 16+ HCP and does NOT deny a 4 card major both partners now to bid 'up-the-line'.

Handling Intervention

In general except where indicated below BETA aims at not being diverted from nornmal methods:
Opponent Doubles:

Redouble shows 8+ HCP denies a diamond fit or a 4+ card Major. If holding a Major or support then these bids are to be made as usual. That's 1Ma, 2Ma, 2D or 3D as usual

If RHO overcalls in a suit, a negative double denies a diamond fit, but implies holdings in any unbid suit. Strength depends on the level: 1L: (7)8+; 2L: (9)10+; 3L: (11)12+.
1D-*-1Ma is a naturall response shows 4+ cards <14HCP: -2Ma shows 5+ cards & 10+ HCP
Importantly any new suit bid at any level bid denies the foregoing HCP and is pre-emptive in nature.
A direct classical 1NT 5-9 HCP Balanced

Opponent overcalls 1Ma:

1♦-(1♥ opp)-* Shows 4+ Spades, 1♦-(1♠ opp)-* Shows 4+ Hearts - again mirrors treatment follows a 1♣ opening
A 2NT bid following any simple overcall shows a solid raise to at least 3♦. 'Trustcott'; but denies any non-bid Major

3 level bids in a new suit are 6+ cards & Pre-emptive - break-outs in BETA parlance!
Game level bids are natural and usually distributional hands

BETA does not use splinters over opening bids
1D with a 3♣ rebid, with OR without a jump announces a 5+-5+ or better in the minors - this following any response by partner or any opponent intervention! This rebid will retain this meaning even if opponents interfere at the 3-level - a 4♣ rebid still signals both minors!

See: Handling 5-5 Hands. 3N is the only forcing continuation by responder which may not be passed!
If opponents intervene above 3N then double instructs the opener to describe his distribution in 4 steps.

Opener's Rebid summary 1♦ - 1♥

2♥                            Natural raise also 3 & 4
1♠                            4 card Spade suit - denies a 4+ card heart support (but with 3 card support Prefer a 1N 12-16 rebid)
2♣                             4+ card Natural. 9+ HCP. Denies any Major interest
1N                                 12-16 Balanced. 2♣ Crowhurst inquiry available - Beta standard See above 'similarities with a 1♣ opening'.
J2NT                          17-18 Balanced. Invitational. Opener denies a 4 card fit responder can show a 5¦6+ card major suit - as over a 1NT rebid by transfer (5) rebid (6+)
4♣ or 3Ma' (Splinters) Shows 4+ card support and a shortage in Clubs or the other Major. Note in Beta Splinters are never used in BETA in direct response to any opening bid.
2|3 Ma                            Limit bids without opp intervention, pre-emptive with opp intervention
2NT(trustcott) Sound raise to at least the 3-level ONLY with opp intervention.
Jump in a new Major suit rebid Beta Std: (E.g.: 2 other Ma') This jump rebid by opener is valid in all sequences. It promises: (15)16+ HCP, A 2-3 card short suit with ideally 2 top honours, in a single suited hand
3♣                                 5-5 or better in minors <=7LTC.
2♦                                 Shows a 6+ card suit. 10-14 All rebids show 6 cards in BETA

Opener's rebid after 1♦- 1NT -? [Responder has neither singleton, Major or void|singleton - moderate values 6-9HCP]

PASS             To play
2♦             Shows 6+ Diamonds <15HCP
2¦3NT                       Natural, balanced limit bids
3♦          15+HCP, quality 6+ card suit single suited hand
Jnew suit (NOT ♣'s)    Beta bid: (15)16+ Shows a Short suit (1)2-3 cards with top controls - Never shows a void but a singleton Ace is acceptable.
3♣                                  5-5♦_♣ <=7LTC