One of things that system designers look at is how opener's 17/18+ hand types handle common jam situations. With responder just passing and opener to make first rebid, three measure points often considered are:
Opponents reach three of the highest unbid major (e.g. 1C-1S-Pass-3S--?)
Opponents reach four of the highest unbid major (e.g. 1S-2H-Pass-4H--?)
LHO (of opener) jumps to three of highest unbid minor (e.g. 1C-3D-Pass-Pass--?)
When these measure points are looked at, the standard and multi-way club opening systems are in some trouble. For example, it goes 1C-2S-Pass-3S--? in standard: now what does 18-19 balanced do - double for takeout, or try 3NT and find partner with nothing, or pass and find partner had a little something? Likewise, it goes 1C-1S-Pass-4S--? with a Polish Club 1C - are most 18-19 hands going to double here, and if they don't then too many times the partnership will end up in a bad spot in the five level.
If one plays a Mexican 2D opening (or uses something like BRASS - see
http://www.bridgematters.com/brass.pdf ), then the 18-19 balanced hands are taken out of the minor suit openings. So after 1C-1S-Pass-4S--Double-Pass-?, responder knows that opener has a club suit and an unbalanced hand, and is better positioned to take appropriate action than in standard. One can see examples of this by looking at hands in the past few years of the Italian World champions.
One idea is to use the 2C opening to handle 18-21 quasi-balanced (named QBal: balanced or close to balanced, can be a 5-4-3-1 for example). This allows opener to express the approximate values in one shot. Let's look at an example framework:
1C: Natural, non-forcing, either:
-- a) Cs, unbalanced, 10/11-17
-- b) Balanced, 11/12-14
-- c) Cs, 17/18+ to near GF, not-QBal
1D: Natural, forcing, with:
-- a) Ds, unbalanced, 10/11-17
-- b) Ds, 17/18+ to near GF, not-QBal
1H/S: Natural, 5 or longer, 10-17, or 17/18+ to near GF not-QBal
1NT: 14/15-17 balanced
2C: 18-21 QBal, not forcing (can be passed with Cs and weak)
2D: Either:
-- a) 21+ QBal, but if just 21-22 then with a singleton
-- b) Any game force
2NT: 21-22 balanced
Rest: Preemptive package
So the 2D opening is somewhat overloaded - it is hard to unwind that much in so little bidding space - however the frequency is relatively low, so any damage will not occur that often. What one gains in this framework is putting the 1-level openings in a nice position, both for constructive and competitive bidding.
Like most system designs, the proof is in the pudding - the pudding of playing thousands of hands in reasonable strong fields and seeing what happens. For system lovers, this means trying to get some partner to play it - then after the thousands of hands if it turns out to be ineffective, one has a not-too-pleased partner, or ex-partner.
--- ---
A lot of system design is considering sets of hands, and then placing these sets in one spot or another. Here's a posting I made on rec.games.bridge in 2000 about the placement of these sets:
- A lot of system design revolves around the meanings to attach to the opening bids of 1C, 1D, and 2C, and what range of a balanced hand that a 1NT opening should show. Designers must determine how to unwind bids later in the auction, especially when faced with interference by the opponents.
- For discussion purposes about the set of meanings, assume that ranges of meanings can be Ordinary (about 11-14), Intermediate (14/15-17), Strong (17/18-21), or Big (22+). Also meanings can be Balanced or Unbalanced.
- For an opening bid, the meaning containing the lowest range of strength is the one that responder has to be first concerned with, in order that the bidding does not reach too high of a contract. For example, after a standard 1D opening, responder must first be concerned about opener having 11-14, even though opener could have much higher values. This is extenuated by the probability that opener is more likely to have less points than more points (assuming a minimum of 10/11).
- In competition responder must be concerned about opener's balanced hands, since these will be less likely able to bid freely. The distribution of unbalanced hands often provides opener with another call later in the auction.
- For a standard 1C opening, we can say it has the following meanings:
--1) Ordinary, Balanced, 3+ clubs.
--2) Ordinary, Unbalanced, 4+ clubs (5+ usual).
--3) Intermediate, Unbalanced, 4+ clubs (5+ usual).
--4) Strong, Balanced, 3+ clubs.
--5) Strong, Unbalanced, 4+ clubs (5+ usual).
Responder's first concern is 1), and then next is 2). If opener has 3) and responder is unable to describe hand or show values, opener will often be able to take another call. Likewise for 5). 4) is an interesting case - opener will sometimes be able to make another call, such as in the sequence 1C-1H-Pass-Pass--1NT, but sometimes opener is faced with a real guess such as 1C-3H-Pass-Pass--?. However what helps the standard 1C opener in making the guess is that responder, in the example case, has been unable to support clubs, or make a negative double.
- Playing a weak notrump standard system (e.g KS), the opening 1C bid does not have meaning 1) above, but now has meaning: 1b) Intermediate, balanced, 3+ clubs. For this system responder tends to be concerned about whether opener has meaning 1b) but also must be careful not to press too high in case opener has meaning 2). Hand type 4) becomes a little easier in competition since responder will endeavour to bid in case opener has hand 1b). So after 1C-3H-Pass-Pass--?, opener knows responder will try to find a bid in case opener has 1b), so with 4) close cases can be passed.
- In the proposed idea (that this post came from), 1D shows 11-18 balanced so there are essentially two meanings:
--A) Ordinary, balanced
--B) Intermediate, balanced
Responder must first be concerned with A) in the face of competition. However B) does not provide easy entry into the later auction. For example after 1D-3H-Pass-Pass--?, opener knows responder must worry about A) first, but holding B) opener knows that partnership might have the values for game, yet opener is not strong enough to bid over 3H, except perhaps with a double if short in hearts.
- It would be better if 1D had a stronger minimum strength or used a split range. If 1D was 15-21 balanced, responder could worry about the 15-17 balanced hand, and opener, if holding 18-21 could take a later bid. Likewise if 1D was 11-14 or 18-21 balanced, responder could worry about the 11-14 hand type and opener could bid again with the 18-21 hand type.
- One might ask if it is better to use a split or stronger minimum approach. Personally I believe in the Either/Or Principle (Anders Wirgren) so I like the split.
- The Nightmare system has a well thought out scheme for openings. In particular 1C is either:
--N1) Intermediate, Balanced
--N2) Intermediate, Unbalanced, 4+ clubs (5+ clubs usual)
--N3) Strong, Unbalanced, 4+ clubs, (5+ clubs usual)
--N4) Big, Any.
Responder's first concern is N1, knowing opener can often call again if N2 or N3, and that N2 will often know when to stay quiet if responder could not bid. 1D is either:
--D1) Ordinary, Unbalanced, 4+ diamonds (5+ diamonds usual)
--D2) Intermediate, Unbalanced, 4+ diamonds (5+ diamonds usual)
--D3) Strong, Unbalanced, 4+ diamonds (5+ diamonds usual)
--D4) Strong, Balanced
Responder's first concern is D1, knowing the opener often has another bid holding the other meanings.
- In one of my systems I try this for 1C:
--G1) Ordinary, Balanced, 3+ clubs
--G2) Ordinary, Unbalanced, 4+ clubs but not too distributional (not decent 6-4 or 7+ clubs)
--G3) Strong, Balanced.
--G4) Strong, Unbalanced, 4+ clubs (5+ usual)
--G5) Big, any without 5+ in major unbalanced or very distributional without clubs.
Responder's first concern is G1 and then G2. Basically 1C is a standard 1C opening with the Intermediate Unbalanced taken out [hand type 3) way above], G5 added in, and G3 allowed to have any balanced, not just with 3+ clubs and no five card major.
- One can map out the meanings for systems such as Precision or Polish.
Anyways if you are still reading at this point congratulations and I would appreciate any comments you have on the issues given above, especially if you disagree.
--- ---
That ending ("if you are still reading") is as apropos today as it was back then! These system design issues are interesting, but only to a limited few of us.
--- ---
So a key concept that could be used is that an opening consists of a base meaning, and also of stronger meanings that are related, but that have sufficient strength and/or shape to be able to handle themselves if the bidding gets competitive. Also, in non-competitive auctions, these stronger meanings can be shown by jump rebids, since they have the strength and/or shape to play there.
Let's look at a multi-tiered example, using some influences of Miles's Unbalanced Diamond, and the far earlier Katz-Cohen Breakthrough system. The "we have to get to the two level" break point here will be between 18 and 19.
1C: Intermediate or Big QBal, artificial, forcing, either:
-- a) All 15-18 QBals with 18+
-- b) All 23+ QBals with 18+
1D: Unbalanced "Diamond" (either minor) approach, either
-- a) 10-14, not balanced, no five card or longer major
-- b) Long minor, 15 to 18, not-QBal
1H/S: Natural, five or longer, either:
--a) 9-14
--b) 15 to 18 not-QBal
1NT: 11/12-14, balanced
2C: 19-22 QBal
2D: Multi. Either:
-- a) Weak-two in either major.
-- b) 5 card or longer major suit, 19+, not-QBal
2NT: 19+, long minor, not-QBal
Rest: Preemptive package
So for the 1 level suit openings, responder focuses on the high frequency a) option, knowing if opener has b), opener will be able to show it later. As you can see there are many twists that one could apply here to create your own versions.