why is it called NON Natural System

[majraj]

what is Natural in 2C GF ?

[P_Marlowe]

what is Natural in 2C GF ?

Just a guess ..., because most bids except the most infrequent

one (and by a large margin) show the suit implied by the bid?

 

With kind regards

Marlowe

[hrothgar]

what is Natural in 2C GF ?

Just a guess ..., because most bids except the most infrequent

one (and by a large margin) show the suit implied by the bid?

 

With kind regards

Marlowe

Laughable comment if you're playing 3 card minors...

[1eyedjack]

what is Natural in 2C GF ?

Just a guess ..., because most bids except the most infrequent

one (and by a large margin) show the suit implied by the bid?

 

With kind regards

Marlowe

Laughable comment if you're playing 3 card minors...

Heh - well it's still a contract suggestion :-)

[helene_t]

what is Natural in 2C GF ?

Just a guess ..., because most bids except the most infrequent

one (and by a large margin) show the suit implied by the bid?

 

With kind regards

Marlowe

Laughable comment if you're playing 3 card minors...

Agree. Precision, EHAA, Fantunes, WJ and Magic Diamond are all more natural than SA, allthough it could be argued that ACOL is even more natural than most of them.

 

I think it's called non-natural in the meaning of non-orthodox. Most people haven't thought so deeply about what the word "natural" should really mean.

[rbforster]

what is Natural in 2C GF ?

It must have been natural since I saw my RHO open 2C and LHO pass with a bad hand :).

[Free]

"Natural" just means that it's a standard treatment. It has nothing to do with the natural meaning of bids. Most players play stayman and transfers, but there's nothing natural about these conventions. However, since it's adopted in most standard systems, it's considered "natural".

[goodwintr]

Free thinks "natural" means "standard." That can't be right: if one means to say "standard," then one ought to say "standard."

 

I once had a partner who, when asked what kinds of leads he played, would say "natural." I guess he, too, thought "natural" meant "standard."

 

It would make just about as much sense to say that "natural" means "good," and "non-natural" means "bad."

 

The ACBL defines a "natural" bid: the definition is something like, "in a minor suit, it means at least a three-card suit; in a major suit, it means at least a four-card suit." That this definition is arbitrary is readily apparent. As far as I know, the League doesn't have a definition for a "natural system." (Interestingly, it does have a definition for a "relay system" -- not that the definition is easily understood.)

 

I suppose when you come right down to it, a "natural system" is one in which the opening bids and responses are predominantly "natural" in the above sense. (Of course, this begs the question of what "predominantly" means. . . .)

 

 

 

TLGoodwin

[blackshoe]

I suppose when you come right down to it, a "natural system" is one in which the opening bids and responses are predominantly "natural" in the above sense. (Of course, this begs the question of what "predominantly" means. . . .)

Indeed it does. :P

 

My understanding is that the distinction between "natural" and "non-natural" came about as a way to distinguish between the then (and now) predominant systems where most opening bids were natural, save 2 ♣, which was (is) artificial, and the "new" "forcing club" systems (particularly Precision) where 2 ♣ is natural and one ♣ is the artificial forcing opening.

 

Seems a silly distinction to me - each system is predominately "natural", with one artificial forcing bid. One system is in no way more "natural" than the other, save that one is less familiar to the vast majority of players than the other.

[david_c]

Didn't we have a similar discussion about "semi-forcing" recently? It's just a name, it doesn't have to make logical sense in order to be understood. We all know what it means to call a system "natural", so what's the problem?

[tlgoodwin]

The "problem" is that accurate terminology is an aid, whereas inaccurate terminology is a hindrance, to understanding.

[the hog]

"Natural" does NOT mean "standard" treatment, (after all, who knows what standard treatments really are anyway). Natural means NATURAL, in other words, a suit, a contract suggestion etc.

[helene_t]

We all know what it means to call a system "natural", so what's the problem?

Nope. There was a story here on the forum about a tournament stating in its rules that only natural systems were allowed - one pair got kicked out for playing a 12-14 1NT opening, justified by reference to the obvious fact that 12-14 is not a natural notrump range. And I've met players who think that a preemptive single jump is not natural while a preemptive double jump is. And some would say that a take-out double is natural while a take-out 4NT is not. And the old style BBO CC form talks about "natural leads - I never understood what that meant.

 

ACBL thinks that short minor suit openings are natural. And Frederick thinks that Jacoby transfer and Stayman are natural. I suppose that the multi 2♦ is natural in the Netherlands while the Precision 2♦ opening is natural in China. This is already muddy at the national level, but in an international forum, the information content of the word "natural" becomes zero or maybe even negative.

 

I think that a call's naturalness should be on a scale of 0% to 100%, defined as:

- If a bid: (p-q)/(1-q) were p is the posterior probability that the partneship will end playing in that strain and q is the prior probability.

- If double: (p-q)/(1-q) refering to the event that the partnership will en defending doubled or play in the doubled strain.

- If rdbl: (p-q)/(1-q) refering to the event that the partnership will play in the rdbled strain or defend doubled.

- If pass: (p-q)/(1-q) refering to the event that the partnership will defend or, if the last call was made by the partnership iselfs, play in that strain.

 

A system's naturalness should be defined as the average naturalness of all bids made by players of the system, weighted by frequency. This makes a 4-card major system more natural than 5-card majors, especially if the major is opened with 44 Mm as in modern Acol (whether a majors first system like Auken/vonArnim is even more natural I don't know). A weak-notrump system is more natural than a strong-notrump system because a natural 1NT is the most natural opening and the weak 1NT is more frequent than the strong 1NT.

[david_c]

We all know what it means to call a system "natural", so what's the problem?

Nope. There was a story here on the forum about a tournament stating in its rules that only natural systems were allowed - one pair got kicked out for playing a 12-14 1NT opening, justified by reference to the obvious fact that 12-14 is not a natural notrump range. And I've met players who think that a preemptive single jump is not natural while a preemptive double jump is. And some would say that a take-out double is natural while a take-out 4NT is not. And the old style BBO CC form talks about "natural leads - I never understood what that meant.

 

ACBL thinks that short minor suit openings are natural. And Frederick thinks that Jacoby transfer and Stayman are natural. I suppose that the multi 2♦ is natural in the Netherlands while the Precision 2♦ opening is natural in China. This is already muddy at the national level, but in an international forum, the information content of the word "natural" becomes zero or maybe even negative.

As Ron said above, "natural" is not the same as "standard". In many of these examples you mean "standard"; "natural" has nothing to do with it, except for those [many] people who seem to confuse the two terms. But I believe that the readers of this forum do know the difference, which is why I wrote "we all know".

 

Anyway, the point I was hoping to make was that there are two different contexts in which you might use the word "natural". When talking about bids, a natural bid is one which (roughly speaking) either shows the suit bid or shows willingness to play there. But we also talk about natural systems.

 

When you have a group of systems which all have a feature in common, it is helpful to give them a name. For example, we talk about "strong club systems", which all have a similar definition for the 1♣ opening. So, what name are we going to give to systems like SA and Acol? Well, we've chosen to call them "natural". It's a reasonable name to use since their distinguishing feature is that bids at the minimum level are natural. Obviously it's not a perfect name, since as the original poster pointed out, not all bids in these systems are natural. But that's the name that's in common use, so let's use it.