1S Opening bid

   

Requirements

Due to the critical need to enter the auction when holding a Major suit: the requirements are lower for the Majors by comparison to other suit openings: 1: 11+; 1: 12+;1N: 12-14.
  1. With balanced hands with 5 Spades we open: 2 with 23+; 2N with 21-22; & 2 with 19-20 & rebid 2N
  2. Single suited hands with 5+ Spades and 3 1/2 LTC or less: Open 2 and rebid with a Spade Trump request
  3. With 5+ Spades and 4 in any other suit with 4-5 LTC : open 2 and rebid +1 in the other suit if partner bids either 2N.
  4. With 6+ Spades and 4-5 LTC: open 2 and rebid 3|4 with 5  or 4 LTC respectively, when partner inquires with 2N. 
  5. A 3rd hand opening of a weak 2 can be made on a 5 card suit.
Responses:
A direct Jump to   3 |♦|:  Shows a 7+ card suit weak 3-7 HCP - Break-out.
2NT: BARON (15)+ HCP response balanced hand (no 5 card suit) can be shaded to 15 ONLY with minimum support for Spades - Qx or better - 2nd step trump response. A Baron bid invites bidding up the line for both players up to 3NT.
A rebidded suit shows 5+ cards any missed suit denies a 4 card holding.
Note: over any intervention 2NT becomes Trustcott showing 4+ card support and payable at least at the 3-level.
2: Needs minimum support: Hx or xxx & 4-8(9). This is can be somewhat pre-emptive or a sound raise. Opener can rebid in a new suit trial-bid. with 15+.
3: Limit BUT pre-emptive following intervention.
4: To play
4♣|: See SWISS bids. Shows 4-5 card spade support, a balanced hand & a solid raise to 4 - available even if opponents intervene! Note: In Beta direct splinter bids over opening bids are NOT used.
2♣|: Response shows a good 9+HCP. Minimum requirements are a 4+ card suit headed with Ace|King. This must be adhered to or partner may miss a game. This bid is Forcing. It may also be the debut of a DGR (delayed game raise) sequence shown by a rebiding 4 or by rebidding the 4th suit. Opener with additional values may investigate a slam.  An alternative continuation arises when opener bids a 3rd suit - now 4th suit rebid by responder is a cue-bid also promising at  least 3 card support for Spades with slam intent.
2♣|: Can also be a 6 card suit and 5-9  HCP. Subsequent Rebid of 3♣| shows this and is a STOP bid (this is always true in Beta that when responder rebids his initial response!)
Cue-bid: When 1 was an overcall. This shows invitational values 13+ and <3 card spade support and no 5 card un-bid suit. Forcing for 1 round. Overcaller can rebid a 6 card Spade suit;  show a second suit; else 2NT minimum.
2: Shows a 5 card suit & 10+ HCP
1NT: Ideally 5-7(8) HCP. No other bid available. If the 2
asking rebid is agreed, preferred with Beta, then the 1N range is extended to 10(11) HCP  especially to cater for when holding a 5 card red suit. A 2! rebid (non-forcing) requests a  5 card red suit, or to choose between the black suits.
The logic behind the sequence 1-1N-2! Where 2 is artificial is given below,

Rebids by opener

There are 2 rebids in Clubs to take special note of:.  The first handles 5-5 or better distributions in the Black suits:-

1
-any-3    Shows 2-suiter 5+-5+ in & 4-7 LTC   Responder may use 3NT to explore distribution or show preference. See theory
The following gives a weak responder 5-9HCP a chance to declare a  5 card RED suit or to select preferred Black suit!1-1NT-2  Conventional bid. 1NT bidder to show a red suit if possessed - else to PASS(preferring Clubs) or bid 2 (preferring Spades)
                        [Important note: this conventional sequence is only available following a 1 opening]
1-1NT-PASS Enough
1-1NT-2   To Play - probably 6 card Spades
1-1NT-3 Forcing, Natural 5-5 4-7LTC - 3N asks distribution can also be 6-5 or 6-6 Otherwise PASS or correct
1-2♣|| -?   Normally forcing responses 10+ HCP.  UNLESS responder rebids his suit at his next bid.