Archived from groups: rec.games.mahjong (
More info?)
"Ryan C. Morris" <rmorris2001@hotmail.com> wrote in message
news:cb37f914.0406150146.6ac6a58c@posting.google.com...
> Greetings fellow Mahjong afficiandos:
>
> About the issue regarding chows...
>
> The method for counting Chow-based hands is,
> to be frank, convoluted.
> Although Vitaly Novikov made a valiant attempt
> to break the system down into sensible parts,
> I believe that it scored 4 points for:
>
> C. B123+B456 C123+C456
>
> ...when in practice this pattern scores only 3 points.
>
Thanks Vitaly and Ryan for sharing the meaningful explanations. I am quite
used to "going by the book" ^_^ After having re-studied the Chinese version
of Chinese Mahjong Contest Rules ("CMCR"), I am afraid my explanations could
be quite different.
To begin with, I took time translating the Chinese rules of article 10.1(5)
as follows:
Article 10.1(5) The principles for computing the basic points
The "Table Of Score Elements" of The Rules is where the computation of
scores of a winning hand shall base on. Upon winning, the major score
elements shall be selected based on the "Table Of Score Elements", and all
possible score elements that are not implied in others shall be formed and
scores of which are added. In addition, when computing the scores the
following principles shall be observed.
1. Non-Repetitive Principle
If a score element shall, at and due to the nature of its formation, imply
the existence of other score elements, then scores of such other score
elements shall not be counted.
2. Non-Separation Principle
When a score element is selected, the combination of its own cannot be
separated to form a new element for further scores.
3. Non-Identical Principle
Pais that have been used to form a score element cannot be used to combine
with other pais to form an identical score element for further scores.
4. Select Higher Principle
If two sets of pais can form two or more score elements but only one of
those elements can be selected, the element with higher scores may be
selected.
5. Select Once Principle
Any pais that have not been used may be selected only once to combine with
pais in other score elements to form a new score element.
For the purposes of easy references, the beginning portion of the article
may be referenced as art. 10.1(5) while the 5 principles shall be referenced
as art. 10.1(5)1, art. 10.1(5)2 and so on.
Now, with Vitaly's sample hand:
> C. B123+B456 C123+C456
I have the following interpretation:
B123+B456 (1 point)
C123+C456 (1 point)
- The above two score elements are selected based on art. 10.1(5).
Can we *also* select
B123+C123 = 1 point, and
B456+C456 = 1 point, for a total of 2 *extra* points?
The answer is no because you can only select one combination (either this
one, or the previous one), as stipulated by art. 10.1(5).
[My previous explanation using art. 10.1(5)1 might sound a little bit
deviated but is also applicable, since (B123+C123) and (B456+C456) are
implied in the existence of B123+B456 and C123+C456.]
If B123456 and C456789 co-exist, you can select only B123456 and C456789 for
2 points, as per art. 10.1(5).
In the following I would like to add some comments to Ryan's explanations
and I base on the CMCR rules as outlined above.
> The following is a description of what I and a number
> of teachers of the rules have used to describe
> the method for scoring chows. It involves a concept
> of "using up" chows once they have been counted.
>
> 1. Take the largest grouping of chows that compose
> a hand.
> For example, Mixed Shifted Chows (3 chows), Mixed Straight
> (3 chows)Pure Straight (3 chows), Pure Double Chow (2 chows),
> Mixed Double Chow (2 chows), or Short Straight (2 chows).
> Define this grouping of chows as "used" and count the points.
> If you have "used" 2 chows, go to step 2. If you have
> "used" 3 chows, go to step 3.
>
> 2. Now that you have "used" 2 chows, you may attempt to
> use your 3rd chow if you have one. If the 3rd chow can
> be added to some part of the 2 "used" chows, then you
> may add it and score the appropriate points. However, it
> can only be added to 1 one of the "used" chows, not both,
> therefore it can only score up to 1 extra point
> (once you have "used" B123 456, adding B123 scores a point
> from combining with either B123 (Pure Double Chow) or B456
> (Short Straight), but not both).
This is in line with art. 10.1(5)5. However, my different understanding is
that sets that can be formed into score elements shall be formed first, as
per art. 10.1(5), and only set(s) that cannot be formed into score elements
may apply the principle of art. 10.1(5)5.
>
> 3. Now that you have "used" 3 chows, you may attempt to
> use your 4th chow if you have one. The 4th chow may be combined
> with one, but not more than one, of the used chows.
This is in line with art. 10.1(5)5.
>
> Example 1:
> B123 456 C123 456 (Total: 3 points)
> Use B123 456 for 1 point. (Short Straight)
> Add C123 to B123 for 1 point. (Mixed Double Chow)
> Add C456 to C123 (Short Straight) OR add it to
> B456 (Mixed Double Chow) but not both for 1 point.
> The total is 3 points.
>
> Note that the following pattern yields the same 3 points:
> B123 456 C456 789.
This is different with my "2 points" interpretation.
>
> Example 2:
> B123 456 789 789 (Total: 17 points)
> Use B123 456 789 for 16 points. (Pure Straight)
> Add B789 to B123 (Terminal Chows) OR to B456
> (Short Straight) OR to B789 (Mixed Double Chow)
> but not to more than one.
This is in line with art. 10.1(5)5.
Let me know if I have any mistake interpreting the rules.
Cofa Tsui
www.iMahjong.com
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