[nullve]

I have the feeling that many who are more than willing to play wide-ranging NF rebids by Opener such as

1x-1y; 2z(z<y) = "10-15, 4+ z"

(or even

1x-1y; 2z(z<y) = "11-18, 4+ z",

as in standard 2/1), would consider a 1N opening with a similar range, e.g.

1N = 11-16 BAL,

to be dubious at best.

What good reasons could they have?

[awm]

1. More likely to have a safe contract in a suit (more likely to have a fit, more likely 3m plays well with shape in at least one hand, etc)
2. More likely to find a suit fit if we have (4-4 minor partial very hard to find after 1nt for example) because of the extra space.
3. Safe 2x correction on many marginal hands (like 7-9 hcp not a "real invite") on the second sequence where no such safe spot exists after 1nt.
4. Range may actually be a bit narrower than you suggest since not all 10-11 open, some 18 force game, etc.
5. In any case this is one of the bad things in standard bidding and more a "least of evils" situation than something desirable. Balanced hands are more frequent so missed games on them a higher price to pay.

[steve2005]

Is Z<X?
Why is this in non-natural System discussion, bidding seems natural?
Crowhurst came up with a wide-ranging 1N rebid in Acol of 12-16, 11-16 seems too wide.

[Zelandakh]

nullve, on 2017-March-24, 10:08, said:

What good reasons could they have?

In addition to the points raised by Adam, the theory of bidding systems has a concept of one bid hands versus two bid hands. As a general rule, balanced hands fall into the former category, even though there are few, if any, systems that are able to have a single bid for all ranges. With single bid hands we typically want to get across a fairly well-defined description of our hand and let partner steer the remaining bidding.

Two bid hands are different. Usually these are more complicated hands and we will often then need a third call to further clarify shape and strength. Because we are expecting to be describing further, it is acceptable for two bid hands to be less well-defined.

As Adam has already pointed out though, the extremely wide range of rebids used in standard methods are a well-known weakness. This is part of the justification of the range used in Polish Club for example, as well as an obvious advantage for Precision. And, just for your comparison, my system uses effective rebid ranges of 10-13 and 14-17 opposite a stronger Responder - perhaps this is tight enough for you? Opposite a weak responding hand the ranges change to 10-15 and 16-17.

Here you can see the 10-15 range you gave; but is that really an issue when it is known that no game is there on pure power? The point here is that the width of the range is only relevant in the context of partner's range. In the end we get an advantage if we can split the hands up into more ranges. If you have ideas on how to achieve that within a natural context they could be valuable. Strong club and diamond systems have means to reduce the ranges at the cost of introducing other weaknesses.

[rhm]

nullve, on 2017-March-24, 10:08, said:

What good reasons could they have?

May I ask what criteria you have for "good" ?
Good is in the eye of the beholder.
Many of the bidding ideas, which are now commonplace, were originally frowned upon.
For example negative doubles, 2/1 as game forcing and corresponding wide ranging notrump responses etc.
Today, even in the expert community some consider conventions like Flannery a waste of a valuable bid others consider it brilliant.
The same holds true for Bergen raises. The list is almost endless.
Of course not all ideas, which are new, will stand the test of time.
But what are good reasons is in the eye of the beholder and it is almost impossible to predict what will stand the test of time.

Rainer Herrmann

[gwnn]

After
1H-1S
1NT (12-17) as described by Frances at some point, you have a cheap ask with 2C after which you'll be able to stop in 2M if opener is minimum (maybe only 2S, depending on how you split up your ranges, but still).

After
1N (12-17)-? you'll need to have a range ask but no known suit to sign off in when your partner (as usual :x) shows up with a minimum.

The same applies for 1x-1y; 2z but you have 3 different suits to sign off in. You will occasionally play in 3m instead of 2. Oh well.

[johnu]

nullve, on 2017-March-24, 10:08, said:

I have the feeling that many who are more than willing to play wide-ranging NF rebids by Opener such as

1x-1y; 2z(z<y) = "10-15, 4+ z"

(or even

1x-1y; 2z(z<y) = "11-18, 4+ z",

as in standard 2/1), would consider a 1N opening with a similar range, e.g.

1N = 11-16 BAL,

to be dubious at best.

What good reasons could they have?

I don't understand the willing to play wide-ranging NF rebids comment. What choice do you have? e.g. Make a jump shift with 14-15 to distinguish those hands from 11-13? (IIRC, that was part of CC Wei's Precision system in the original booklet).

In a natural based system, you don't have any other good option but to play those wide ranging rebids. If there was a way to play narrow range suit rebids without negatively impacting the rest of your system, I'm sure everybody would do so.

On the other hand, almost every system designer designates a narrow range for

1m 1x
1NT

auctions, and most experts at least frequently open 1NT (or play artificial methods) if the HCP are in range for reasons listed by other posters.

[nullve]

johnu, on 2017-April-01, 00:40, said:

I don't understand the willing to play wide-ranging NF rebids comment. What choice do you have? e.g. Make a jump shift with 14-15 to distinguish those hands from 11-13? (IIRC, that was part of CC Wei's Precision system in the original booklet).

In a natural based system, you don't have any other good option but to play those wide ranging rebids.

I don't play any wide-ranging rebids in my 2/1-like system, at least not in the usual sense. E.g. this is what I play over 1♠("10-21, 5+ S, unBAL")-1N("5-12, NF"); ?:

P = "10-12", 5S3-H
2♣ = "10-15", 4+ H OR "16-18", any [similar to awm's Gazzilli]
2♦ = "13-15", 5S3-H4+m
2♥ = "13-15", 6+S3-H
2♠ = "10-12", 6+S3-H
2N+ = "19-21"

The 2♣ rebid is wide-ranging in some sense, but over 1♠-1N; 2♣,

2♦ = "8+", but not 1-S3H if "8-10"
...2♥ = "10-12"
...2♠ = "13-15" [the reason why Responder shouldn't have "8-10", 1-S3H]
...2N+ = "16-18"
2♥ = 5-7, PREF opposite 5S4H / "8-10, 1-S3H"
...P = "10-15"
...2♠+ = "16-18"
2♠ = "5-7", PREF opposite 5S4H OR "4-6", 3 S
2N+ = "5-7", usually 1-S2-H,

which avoids problems with the standard or Precision 2♥ rebid that stem from the wide range.

The structure is somewhat incomparable with the standard 2/1 rebid structure, though, since 1N doesn't include a 3c limit raise and thus doesn't even have to be semi-forcing.

It also certainly isn't perfect. E.g. I hate passing 1N with 5S5m (when "10-12" is supposed to be 9-11 hcp), but I can't think of a similar structure where bidding is that much better. The Muiderberg-like 2♦ rebid will occasionally lead to unLAWful or even stupid 3m contracts, as with 13 hcp, 5341 opposite 7 hcp, 1435 after 1♠-1N; 2♦-3♣(P/C); 3♦-P. Yuck!

The point is just that there seems (to me) to be playable rebid structures (over fairly standard as well as Zel's non-standard respones) using no wide-ranging NF rebids (and no wide-ranging rebids in the usual sense), although these structures may come with problems of their own.

[foobar]

"...avoids problems with the standard or Precision 2♥ rebid that stem from the wide range."

In the many years of playing strong club systems, I never thought of this sequence as being especially problematic given the tight (10)11-15 range. Can you please elaborate?

[nullve]

foobar, on 2017-April-01, 23:15, said:

"...avoids problems with the standard or Precision 2♥ rebid that stem from the wide range."

In the many years of playing strong club systems, I never thought of this sequence as being especially problematic given the tight (10)11-15 range. Can you please elaborate?

You will sometimes get to unmakeable 2N and 3♥ contracts after common invitational sequences such as

1♠-1N; 2♥-2N; P

and

1♠-1N; 2♥-3♥; P

when you could have stopped in 2♥ or 2♠ using different methods, e.g. after

1♠-1N; 2♣-2♦; 2♥-P

or

1♠-1N; 2♣-2♦; 2♥-2♠; P

playing awm-style Gazzilli.

There's also more than a one trick difference between (10)11 and 15, so you'd expect some of those 2N and 3♥ contracts to fail for that reason alone.

The situation is (even) worse in standard 2/1, of course, since 3♥ over 1♠-1N; 2♥ is hardly more than a courtesy raise, at least when vulnerable at IMPs.

[phoenix214]

If you play SF NT, you should be usually passing it with flatish min hands that do not have much extra, or are not clearly suit orianted:
With a hand such as QJxxx;Kx;Axxx:Qx, pass should be somwehat clear, with a stronger hand, such as QJxxx;Kx;AQxx;Qx, pass is wrong as you might be missing game. The only wide ranging part comes from the fact that with hands such as AKxxx;x;xx;Kxxxx you have to bid again, as well as AKxxx;x;xxx;KQxx which strongly prefer playing in a suit. If you play Gazilli, then even the bids are limited as you have a bid for the 14-16 5-5's, so usually what you will have is weakish 5-5s or strong/conctrated 5-4s which is still quite narrow IMO.