LAW
OF SIMMETRY, does that exist?
When Declarer has 9
cards fit
(AKJxx - 10xxx or AKJxxx - 10xx) missing only the Queen,
if interference not happen, we play first the Ace and if Queen don't apears we
go to the other side and play low to KJxx and if a low card apears we must
decide: King (for Queen's drop) / Jack (finesse).
The technical way to decide between finesse or drop is using the math of
probabilities that says: chance of finesse is 50% and chance for drop is 53,14%.
However following the Ely Culbertson's pseudo law of simmetry if in our hand or
dummey
there is a singleton we should finesse!
Thus the
question is: does the probability's calculus be influenced by the "Law of
Simmetry" restrited by the distribution of the 52 cards?
A player that already
played many hands of bridge have noticed the strange frequency that some
unbalanced division of the 4 suits for a player corresponds to another
unbalanced
division for other player. A void correspond other void, a singleton correspond
other singleton.
Those situations are mostly often considered mere coincidences without being
given due importance and without being considered valid elements of reference.
Despites mathematically we
can't validate these inferences they occur with a meaning frequence that advance
players prefer to use then for unbalenced hands.
So, the "Law of Simmetry" may be considered a guideline for infere the
probable card distribution of opponents based in our card distribution.
Of course, the "Law of Simmetry" is just an additional tools with the math of
probabilities that allows us to make a decision in the played of a hand when
there are no bidding informations.
The Law of Simmetry can be summarized in two statements:
a) To a balanced hand usually corresponds another balanced
hand and to a unbalanced hand usually corresponds another unbalanced hand
with the same degree of balance.
b) A balanced hand usually corresponds to a suit divided with same balance
between the four players, while an unbalanced hand corresponds a suit with
unbalanced distribution between the players (this suit unbalanced usually belong to
the player that had the more long suit)
According this
pseudo law there is a correlation between types of hands distribution and the suit
distribution among all players, so if a player has a distribution of cards
5422 it is a good chance that another player also have a identical hand, or one
of the four suits have the same distribution 5422.
Thus this law statement that from the character of his own hand pattern a player
can draw inferences concerning the pattern of other hands and of the
distribution of the four suits.
To better illustrate this concept
lets look for each hand
in the diagram below where it is possible to set up a table and observe the perfect
correspondence between the division of each player's cards and the distribution
of the suits.
Let's see the follow diagram in this hand:
KQx
AKJxx
xx
Vxx
Ax
=======
xxx
Qxx
= N = x
Axxxxx
= W E =
Jx
xx
= S =
AQxxxxx
=======
Jxxxx
xxxx
KQx
K
that can be represented in this table:
|
types of hand |
|
NORTH |
SOUTH
|
WEST |
EAST |
Distribution
of the
suits |
|
3 |
5 |
2 |
3 |
|
2 |
3 |
6 |
2 |
|
5 |
4 |
3 |
1 |
|
3 |
1 |
2 |
7 |
So in this table we clearly observe:
- the distribution 5332 in Spades is the same of the North cards;
- the distribution 5431 in Hearts is the same of the South cards;
- the distribution 6322 in Diamonds is the same of the West cards;
- the distribution 7321 in Clubs is the same of the East cards.
It is also easy to observe that the success in a contract of 4
or 4 by N-S dependds on essentially in how the Hearts will be played.
If the general rule to play AK with 9 trumps (AKJxx-xxxx) be follow here based in the math of
probabilities that presume, after the play of the Ace, that the drop of the
Queen has chance of 52,12% and so the King should be played, this contract will
not be done.
But who follows the pseudo Law of Simmetry, after noticed the singleton in
Clubs, make the finesse supposing a correspondent singleton in Hearts.
Of course this argumentation has no math validation and Ely Culberson
(1891-1955) knowing that had used his own experience in boards played to
became a defender of this psedo Law of Simmetry as
also was Easley R. Blackwood (1903-1992) that used the rule: if our short suit
of 4 cards is 2-2 then play for drop, but if it is 3-1 play finesse, or if our
shorter suit of 5 cards is divided 3-2 play for drop but if it is divided 4-1 play
finesse.
/ / /
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