What is a natural system of bidding?
This is a system which entirely results from SALON and
doesn’t incorporate (more frankly, with a few exceptions) anything
besides SALON; no artificial bids, no conventions, and no gadgets.
The system is labeled NABOB, which denotes:
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NATURAL OBSERVANT |
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The Polish acronym is SOSNA [
pine–tree ]: SYSTEM [ system ] ODZYWEK [ of bids ] STYLU [ style ] NATURALNEGO [ natural ] |
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One–Level–Suit Opening Bids |
HT = Honor Tricks |
Four 1S opening bids (S stands for Suit), denote ALL hands approximately
from 4 to 6 HT strong.
The exact minimum strength for 1S is
3 1/2 Honor Tricks, whereas the maximum strength raises up to 6 1/2 HT for the most balanced hands.
NABOB hasn't any natural 1NT opening bid
– 1NT is an
artificial bid, denoting all hands too strong to open 1S.
2S opening bids (S stands for Suit) are natural and preemptive (with
5 winning tricks).
Minimum
Honor Strength
Is the 31/2 HT a properly defined
minimum of 1S opening ?
From the viewpoint of Revealing Extras Directive (RED) – yes,
because an average hand has 3HT, and the 1/2 HT surplus seems to be a sufficient Positive Deviation (PoD).
From the viewpoint of Strength Assurance Directive ( SAD ) – also
yes.
Just see: having 31/2 HT yourself, you will find
your partner with almost 2 HT on an average, to which 1 Long Trick (LT) should
be added, giving a total of 61/2 Offensive Tricks (OT).
Thus, the requirement for a one–level contract is satisfied.
Thus, SAD is satisfied in the more demanding
version „What has been bid – is a contract
to make”; not only in the version „What
has been bid – is a profitable contract” .
Minimum
Distribution
In accordance with RED–1 ( Inform about
the greatest PoD ), the 1S opening bid
should mean that the greatest Positive Deviation pertains to the suit opened.
We assume the following distributional minima for opening bids:
1 minor |
= |
at least 3 cards in the bidden suit |
(with 33 in the minors open the better) |
1 Major |
= |
at least 5 cards in the bidden suit |
(a very good 4–card
suit will do exceptionally |
The average length of a suit opened was found to be:
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1 minor = 4.38 = 4 1/2 |
80% of 1 Minor opening bids are based upon at least a 4–card
suit, thus only every fifth 1 Minor corresponds to an exactly 3–card
suit |
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1 Major = 5.32 = 5 1/4 |
Since the average number of cards dealt to a player in a particular suit
is exactly 3+ ( 3.25 ), hence the respective values of distributional PoDs (Positive
Deviations) for different 1S openings:
1 Minor = +1 1/4 ( but a NeD may also happen! )
1 Major = +2 ( and at least
1.75 in each case ).
The Positive Deviations are significant enough to satisfy the
requirement stemming from RED. The low value of PoD accompanying 1 Minor
opening and an occurrence of NeD (Negative Deviation) seem to be the only
faults.
RED–7 ( „The higher bid – the
greater PoD” ) is also satisfied since PoD for 1 Major opening is
greater than that for 1 Minor.
Finally, PAD–1 ( „The lower bid
– the greater strength or dispersion” ) is satisfied as 1
Minor openings have clearly greater dispersion than 1 Major openings.
The
3–5 Model is the Best
Model „Minor – 3, Major – 5” is no novelty to
anybody, but this one has been sufficiently justified, possibly here for the
first time.
Culbertson's model „1S with a 4–card suit” is clearly
contradictory to both RED–7 and PAD–1, which worsens SAD for 1
Major ). ???
Clearly, model „Minor – 4, Major – 5” would be
the best. However, it is impossible !
The
Model Hand
Taking under consideration that an average hand contains 3 HT, it comes
as no surprise that the average strength of 1 Major opening bid amounts to 4
HT, that is, only a half HT above the indespensible minimum.
The average shape of opener's hand for 1 Suit opening bid is
respectively:
1 Minor = ( 4
1/2 2 3/4
2 3/4 2 3/4
) |
The largest value
corresponds to the suit of opening bid. Some rounding has been allowed for the sake of simplicity. |
1 Major = ( 5
1/4 2 1/2
2 1/2 2 1/2
) |
In the case of 1 Minor opening bid, the differences
between the reported values and the exact ones are greater than the respective
differences for 1 Major opening bids. The value of dispersion for 1 Minor
opening bid is larger than that for 1 Major opening bid. Thus, the maximum
relative error due to the rounding is smaller than it would have been
otherwise.
For simplicity, and considering that the dispersion of
1 Minor is much bigger than that of 1 Major, we assume, however, the following
average distributions:
1 Minor = (
4 3 3
3 )
1 Major = (
5 21/2 21/2
21/2 )
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Example |
from Pikier 10, 1982 |
Fragmentary vision has to be avoided everywhere
!
This rule applies to the game of bridge,
especially to the bidding, including solving both the practical problems at
the table and the more general ones in the theoretician’s laboratory.
Fragmentary vision may lead a theoretician
to strange and unnecessary conventions. These may have appearances of
having been deeply analyzed and scientifically formulated. The Blackwood Convention
is an example. However, a system adopting several such conventions becomes
an incoherent conglomerate, though each sequence by itself seems to be
practical. The only right way to bid is through unified,
synthetic and total vision.
A proper solution to the bidding should
take under consideration all three NSB Directives even if the requirements
of the particular directive aren’t fully met. The optimization process
must not focus on one criterion only. The combined effect of all criteria
should be considered.
Thus, in a particular bidding situation
one needs to select a bid which agrees most to all three NSB Directives. If a
more codified problem arises, then the solution should conform to the corresponding
part of SALON.
The weight (or relative importance) of
each Directive remains unknown, unfortunately. Our choice may vary between
the best bid and the least evil.
I cannot measure the values of PoDs (Positive
Deviations). Neither can I measure the value of dispersion. The precise algorithm
hasn’t been worked out yet. Even worse; the very
axioms are still in cradle.
At this stage, a very general rule seems
appropriate. It is superior to Natural Bidding Style Directives.
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Preparation Meta–Directive |
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Not to violate any Directive in future, one has to envisage a possible
development of bidding; minor deviation are allowed if they prevent
future aberrations. |
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I would like to repeat:
Natural Style of Bidding,
enriched by SALON, constitutes itself a very good way of bidding.
This, however, requires considerable
skill at present, but I hope that as NASA
and SALON are developed the whole task
will become easier and easier.
The exact proof that NSB plus SALON constitute
the most precise way of bidding is still lacking. At present, I have only some
circumstantial evidence which I intend to publish soon. The exact proof
would be the greatest achievement in the history of bridge, I think.
For the moment:
Try to prove that ANY convention
leads to better final contracts than careful natural bidding does !
Now, let’s analyze the examples.
Natural Bidding Style is represented by
NAtural Bidding OBservant.
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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East has three Positive Deviations
(PoDs):
a large one
– in Hearts
a considerable
one – in Diamonds
a somewhat smaller
– in Spades
( please notice that had West opened 1§ East’s PoD in Diamonds would
have been equal to that in Spades )
Therefore, East has to inform about his
PoDs in the following order: © ¨ ♠
1© response would make it impossible to
preserve the above order as the subsequent diamond
bid isn’t forcing (mind: “an
old suit isn’t forcing” rule).
Thus, East should bid 2© which is a game forcing bid. Both his
total strength and his PoD in Hearts justify such a bid. A game forcing bid
enables East to show PoD in Diamonds on the next
round.
As we see, Preparation Meta–Directive ( PMD )
has been fully applicable.
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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West’s opening bid was
based upon 4+ HT of which 1+ constitutes a surplus value.
It has
to be remembered that a single–jump response in a new suit assumes only
3 HT.
The
number corresponds to practical value of the exceptionally ugly minimum
opening bid.
That 1+ surplus doesn’t
have to be immediately announced, yet West should be aware of it.
In reevaluating PoDs (
Positive Deviations ) East’s last bid should be considered.
Certainly, East doesn’t
expect West to have such a good fit in Hearts. Thus, West’s PoDs at
this stage look as follows:
a considerable
PoD in Hearts
three
minor PoDs in the remaining suits.
PoD in each of the remaining
suit is of, more or less, the same
value, ie:
in Spades
– there are four spades
in Diamonds
– a very strong 4–card Diamonds
in Clubs
– since the Ace seems to be more valuable asset after
game forcing response.
Therefore, two rebids may be
considered. Either has some disadvantages:
2NT
– conceals large PoD in Hearts
3©
– conceals smaller PoDs in the remaining suits.
This contradiction may be
solved by applying Preparation Meta–Directive ( PMD ); it is possible,
for instance, to bid 2NT first
and to show PoD in Hearts later, and it seems to be the better decision
than to bid hearts first.
[ Written in 1982. Now, I think a heart bid is
better. ]
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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Certainly, 3¨
(refer to the discussion pertaining to 2© bid).
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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Hearts should be bid, but at what level ?
Now, West has a very large PoD in Hearts (because heart
PoD had been concealed by 2NT).
Some extra strength, having been already
assessed as 1+ HT, wasn’t revealed yet, either.
4© bid meets all requirements stipulated by
both:
RED–7 = The higher the bid – the greater the PoD
SAD–1 = Suit bid means PoD in THIS suit
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J x x x K J x K Q J x
A x |
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A K x A Q 10 x x A
x x x
x |
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Certainly, 4♠ (
„New suit after raise is forcing, even it is a game” )
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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The value of the spade
suit increased. In the light of his bidding so far, West has a Negative Deviation
(NeD) in Clubs.
So West should bid 5§ as indicated by
RED–5 = Fourth Suit means NeD in THAT suit.
Such a bid stresses his strength as stipulated
by PAD–1 ( The Lower the bid – the greater
the strength or dispersion ) and PAD–2a ( New suit is a positive suggestion (strength) ).
4NT would convey
Positive Deviation in Clubs. Moreover, according to SALON presented so far,
the 4NT bid would not
have been forcing.
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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Having qualitatively informed
about his PoDs (©¨ª ),
East has to specify more precisely his values. It seems that only PoD in Hearts has
been sufficiently emphasized. 5ª will show not only some PoD
in Spades but also PoD in Diamonds, the
suit which have been bid before (see RED–1a = Inform about the greatest PoD ).
That’s true that Spades are „an old suit” but not as old as Hearts. Thus, 5ª should be considered a
forcing bid.
The bidding has indicated
precisely a singleton in Clubs. Thus, 6§, expressing a Negative
Deviation in Clubs, would have indicated a void.
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J x x x K J x K Q
J x
A x |
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A K x A Q 10 x x A x x x
x |
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The value of Diamonds increased considerably after
East had indirectly shown large PoD in this suit.
The value of club Ace, and even Spades, also increased.
West hasn’t shown his PoD in Diamonds yet.
Neither did he describe his total strength.
7¨ seems to be the only proper bid.
As you see, Natural Bidding
Style is hardly legible. So it is for me !
Nevertheless, after the
bidding has been concluded West is able to visualize his partner’s hand
to every essential card. East may err a little more.
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