When balanced should be 17+ HCP in most circumstances, an exception by my estimate seems to be 5-3-3-2 with 5 hearts, in this case should be a good 16.
With 20 - 21 HCP and balanced open one club but is a relay through 1c-1d-1h-1s-1NT is 20-21 HCP, if they bid a game force then 2NT next bid shows 20-21 HCP
Pass - Cannot Pass
1♦ - 0-7 HCP points
ALERT - 0-7 HCP says nothing about diamonds
1st & 2nd Seat Opening
1♥ - 8-11 HCP and says nothing about hearts, can do this with a hand that has AK only
- Denies a 5 cards spade suit
ALERT - Game Force says nothing about hearts
1♠ - 8+ HCP and promises a 5+ card spade suit
- Was in section 3 of the book
- Takes up a lot of space for responder to show 5+ spade suit otherwise
- This is unlimited but could be basic game force
ALERT - Game Force with 5+ spades
1NT - 12+ HCP Positive Heart Response
- Modified to create transfer system
- 5+ Hearts
ALERT Hearts and slam possibility
2♣ - 12+ HCP Positive Diamond Response
- 5+ diamonds
- Unbalanced 5 diamonds typically 6+ diamonds expected
ALERT Diamonds and slam possibility
2♦ - 12+ Positive Club Response
- 5+ Clubs
- Unbalanced with 5 clubs or typically 6+ clubs expected
ALERT Balanced hand and slam possibility
2♥ - 12+ HCP Positive NT
- Slam interest NT hand
- Systems on if big hand rebids 2NT
- This makes the memory work a little awkward but protect wrong siding a major contract
- This is the only positive response you can initiate with less than 3 controls
ALERT
2♠ - 5-5+ Distribution (8+ HCP)
- 2NT asks for Distribution
- 3♣ - 5 clubs and major 3♦ asks for major
- 3♦ - both majors
- 3♥ - 5 hearts and 5 diamonds
- 3♠ - 5 spades and 5 diamonds
- Any other suit bid shows own long suit likely 7+
ALERT
2NT - 5-5 in the minors (8+ HCP)
ALERT
3♣ - 4-4-4-1 singleton in the black (8-11 HCP)
- shows spade or club singleton
- 3♦ asks
- 3♥ - shows clubs singleton
- 3♠ - shows spades singleton
- Next bid can be 3NT as a signoff and then use 4♣/4♦ RKC for everything else
- 4♣/4♦ RKC if the black singleton doesn't matter, the RKC is the lowest and highest red cards ONLY
ALERT
3♦ - 4-4-4-1 with singleton in the red (8-11 HCP)
- shows heart or diamond singleton
- 3♥ asks
- 3♠ - shows diamond singleton
- 3NT - heart singleton
- Next bid can be 3NT or pass 3NT as a signoff and then use 4♣/4♦ RKC for everything else
- 4♣/4♦ RKC if the red singleton doesn't matter, the RKC is the lowest and highest black cards ONLY
ALERT
3♥ - 1=4=4=4 (12+ HCP)
- Like positive response must have at least 3 controls to bid
- Ask for controls by bidding partners spade singleton starting first step is 0-3
- Singleton spade
ALERT
3♠ - Long self sustaining suit across from a singleton no outside entries so very solid 7 or solid 8 cards
- example AKQJxxx or AKQxxxxx
- Very likely partner can guess the suit
- 3NT to play
- 4♣ interest slam with your suit ask for singleton or void, denies with 4NT
- 4♦ grand slam interest looking for void ONLY 4NT denies it
- 4NT shows inability to guess the suit so asks responder to bid it
- All other bids are openers own suit and to play
ALERT
3NT - 4=4=4=1 (12+ HCP)
- Like positive response must have at least 3 controls
- Ask for controls by bidding partners club singleton starting first step is 0-3
- Bid 4NT as a sign off with min points do not pass 3NT
- Singleton Club
ALERT
4♣ - 4=4=1=4 (12+ HCP)
- Like positive response must have at least 3 controls
- Ask for controls by bidding partners diamond singleton starting first step is 0-3
- Singleton Diamond
ALERT
4♦ - 4=1=4=4 (12+ HCP)
- Like positive response must have at least 3 controls
- Ask for controls by bidding partners heart singleton starting first step is 0-3
- Singleton Heart
ALERT
3rd & 4th Seat Opening
Partner is already limited to 10 points so positive responses change to 8-10 HCP and bid suit is transfer to the suit above. Should be considered game force so 1♥ is 5+ spades and 1♠ is 5+ clubs 2♣ is 5+ diamonds, 2♦ is 5+ hearts. Bidding 1NT guarantees a 4-3-3-3 or 4-4-3-2 distribution
- 1NT - 2♣ asks for the 4 card suit, should bid 1 below, clubs is 2♠
- In third or 4th seat should transfer with 5 of a minor so 1NT can limit the distributions unlike 1st and second where you show a flat distribution even with 5 in first and second seat
This changes 2♥ to be 5-5 in majors (8-9 points) and 2♠ to be 5 spades and unknown 5+ minor 8-9 points (not written anywhere but why not) and 2NT is 5-5 in the minors 8-9 because you didn't open 3NT