The New Sudoku Players' Forum

[SpAce]

This is not a high priority, but it's something that has been annoying me for a long time. The Turbot Fish family is lacking a name for one its prominent members, which unfairly makes it seem like that member is not as worthy as its well-known siblings and cousins. It sometimes makes exact communication difficult as well. Is it way too late to fix that? It probably is, but who's to blame me for trying!

Here's how I see the two Turbot hierarchies:

Simple types (X-Wing omitted):

Code: Select all

                               X-Chains                   
                                   |                     
                             Turbot Fishes               
                                   |                     
           -----------------------------------------------   
          |                        |                      |
     [Skyscraper]           [2-String Kite]           [???????]


Grouped types (Franken X-Wing omitted):

Code: Select all

                           Grouped X-Chains
                                   |
                         Grouped Turbot Fishes
                                   |
           -----------------------------------------------
          |                        |                      |
[Grouped Skyscraper]    [Grouped 2-String Kite]    [Empty Rectangle]


As we can see, every node but one has a generally accepted distinctive name. Why the hell didn't Havard name that missing one too, when he came up with the since ubiquitous Skyscraper and 2-String Kite!? He called it the real "fish" pattern but didn't really give it a name. It also makes little sense because any one of the three simple Turbot Fishes can assume the distinctive fish shape after which the Turbot Fish family has been named (the only difference is in where the strong links are). Or, maybe he hadn't originally even registered the third type and only listed it after getting to know that the Skyscraper and Kite belonged to a family of three (or four, if X-Wing is counted in). Either way that decision screwed up the hierarchy. Now everyone talks about Skyscrapers and Kites, but the third simple type is all but forgotten. On the other hand, its grouped cousin does have a well-known name: Empty Rectangle.

What are our current options when we need to talk about the unnamed Turbot Fish type? As far as I know, there are basically two of them, and both of them are bad.

1) It can be called just Turbot Fish, and I would guess that most people do. That's a poor choice, however, because it's the generic name for all three of those patterns (+ X-Wing), and thus it should not be used as a specific name for one of them as well. That leads to inexact communication. It could just as well be called X-Chain. Or AIC, for that matter. They're all true but convey less and less information about the pattern.

2) To be more specific, it can be called Empty Rectangle, because it is one -- although with just two members in the hinge box which makes it harder to see as such. That's also a poor choice, because that name is already reserved for its well-known grouped cousin, and almost everyone connects the ER to grouped box candidates only. For that reason Hodoku, for example, does not even recognize the simple type as an Empty Rectangle by default, but it's an option. Personally I've chosen that option (and disabled generic Turbot Fishes), because it's the only way to see all supported Turbots listed by their specific type (Grouped Skyscrapers/Kites unfortunately not supported). I also call it ER in my own chains, which probably confuses some readers. So, it's not a good option either, just slightly less bad than the first one from my point of view. (I guess the simple type could logically be called "Ungrouped Empty Rectangle" to distinguish it, but that would be quite horrible).

So... is there anything we can do to fix this? Like I said, it's obviously not a high-priority problem, but it's something that bothers my love for clean and logical hierarchies and exact communication. Can we come up with a descriptive name for this particular pattern, one that would sit well with its siblings Skyscraper and 2-String Kite as well as its grouped cousin Empty Rectangle?

[StrmCkr]

its a minimal Empty rectangle: fine as a name,
it wont really need another name for the pattern. as its still an ER.

i even had a thread that listed all the extended versions for Empty rectangle intersections. {ERI} that expanded the usages for the ER by expanding the connections to other ERI and or expanding the strong link
unfortunately the tread that listed me as the inventor of the ERI method an advocating it within advances chaining methods as another way to link chain parts...{which was part of that topic} was lost on the crash of the original forums.

would you be exploring all possible ways to minimize the ERI { 5 cells down to 2} and naming every single one of them? {as some have the ERI empty or filled. }

ERI :
the summation of a digit within a box's total cells
where that total = the sum of 1 row + 1 col
where at least 1 row and 1 col must have different active cells for that digit.

the * cells is the empty rectangle intersection which indicate the Row & Col intersection that is used as the link point

Code: Select all

 max - ERI {1 * cell}
|x   /  / |
|x   /  / |
|*x  x  x |
 

Code: Select all

 Minimal - ERI {2 * cells} 
|x   /  */ |
|/   /   / |
|*/  /   x |
 

problem is most people don't know that a minimal version is the exact same as a maximum version, hodoku includes the minimal version as an option thanks to me and turbots where included as a nod to the creator of those move sets.

Code: Select all

bridged Dual ERI
+------------------+------------------+-------------------+
| 567    2456  247 | 1     8     467  | 456-7  9     3    |
| 1678   468   3   | 5     2479  4679 | 1468   267   478  |
| 15678  9     147 | 3     247   467  | 14568  267   4578 |
+------------------+------------------+-------------------+
| 138    238   12  | 6     47    38   | 4(7)   5     9    |
| 4      7     5   | 89    39    2    | 68     36    1    |
| 368    368   9   | 4(7)  1     5    | 2      3(7)  48   |
+------------------+------------------+-------------------+
| 39     34    8   | 2     4579  479  | 5(7)   1     6    |
| 2      1     6   | 8(7)  35    38   | 9      4     5(7) |
| 579    45    47  | 49    6     1    | 3      8     2    |
+------------------+------------------+-------------------+

eri in box 69 connected by a col 4 {bridge}

besides turbots in general where dropped with the advent of u.F.G: where all the patterns associated with it where grouped.
names on some of the small moves stayed for posterity.

just like:
( dual/twin) Sashimi X-wing was dropped in favor of the skyscraper.

some times the u.f.g keeps those names around as well for identifying them.

now if you really want to be technical, Simple colouring ,x-cyles, and turbots are all Fish.

[SpAce]

its a minimal Empty rectangle: fine as a name,
it wont really need another name for the pattern. as its still an ER.

As I said myself, ER is indeed a valid point of view to see it, but it doesn't chime in very well with the rest of the Turbot family. I bet most people don't really see it as a minimal ER -- simply because they don't see the minimal ER as an ER. It's a fact of life, I'm afraid, and there's a reason why that POV is optional in Hodoku. When is the last time you saw someone besides myself call that type of Turbot Fish an ER? I've only seen it called "Turbot Fish" by others, those rare times when it's seen at all. Skyscrapers and Kites seem to take precedence almost always if multiple Turbots including this one are present -- is it only because they're a bit easier patterns to see? Or perhaps also because they have more attractive and distinctive names without any extra baggage? I bet both reasons play a part.



That's why I'd like to give this pattern a fighting chance to get on equal footing with its siblings -- as a named Turbot Fish and not as a special case of ER which few people seem to recognize as such anyway. That doesn't negate the ER POV, of course. It's still an ER even if it has another name, just like a Grouped Skyscraper is still a Finned (Sashimi) X-Wing if one wants to look at it through that POV. ER is just not a great way to see a simple ungrouped Turbot Fish (or any ungrouped X-Chain), I think, because most people associate ERs with grouped hinges only. It's an unnecessarily complicated POV and has too much baggage for this simple purpose (I think your post just made that very clear ).

Also, there seems to be a very clear difference in skills between players who understand grouped links and those who don't. Understanding ERs requires at least some level of understanding grouped links, which makes it a more advanced technique than ungrouped Turbot Fishes. It should be possible to learn all three ungrouped Turbot Fish variants as simple chains without having to learn anything about grouped links or ERIs (which are grouped links). Binding one of them into ER makes that impossible, because it wouldn't make any sense (or be even possible) to study just the minimal ER as a separate concept from the real thing. Understanding a simple box-based conjugate link is easier than understanding the full hinge idea of ERIs.

[rjamil]

Hi StrmCkr and SpAce,

i even had a thread that listed all the extended versions for Empty rectangle intersections. {ERI} that expanded the usages for the ER by expanding the connections to other ERI and or expanding the strong link
unfortunately the tread that listed me as the inventor of the ERI method an advocating it within advances chaining methods as another way to link chain parts...{which was part of that topic} was lost on the crash of the original forums.

Please note that, am not much knowledgeable about subject.

But feel to share StrmCkr's detail explanation regarding minimal and maximal ERI patterns in this post that clear my confusion not only in understanding but provide great help in developing the same.

R. Jamil

[StrmCkr]

Eris aren't complicated minimal or maximum.

it's a conjugate link
row is true or the col regardless of number of cells.

Hence why the only cell u need to know for an eri is the * cells. (which is sweet from a coding point of view)

Eris are the least used as most people tend to use row/cols only forgetting boxes
As the row col patterns actually use less cells, add to the part people tend to pattern match instead of realize not all the x in the pattern need to be present. So only maximum cells are used for Er when they are used. Same with grouped 2-string kites,

Spotting ers are also different, your not checking box for the setup I mentioned before but you could.
You are looking at 4 cells being empty on the same 2 rows and 2 cols in a box, once you spot that you know the other row & col is conjugate.

So search is different for these as well, making them the harder technique to use, Out of the named small fish

Code: Select all

 2-string kite
+-----------+-------------+---------+
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
+-----------+-------------+---------+
| 1  .    1 | .    .  .   | 1  1  1 |
| .  (1)  . | (1)  .  .   | .  .  . |
| 1  .    1 | .    .  (1) | 1  1  1 |
+-----------+-------------+---------+
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  -1   1 | 1    1  (1) | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
+-----------+-------------+---------+

this typical setup causes the most confusion to how these actually work.
box 5 is a conjugate link for cells : but for the sectors use that box area is actually a weak link between sectors Row + Col . {these "patterns" don't use Cells per say but rather the intersections}

in reality its a ( sector * sector = intersection)
Row = (Row * Box) - ( Col * Box) = Col

there is zero difference going from the above to this one.

Code: Select all

Grouped - two string kite
+-----------+---------------+---------+
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
+-----------+---------------+---------+
| 1  .    1 | .    .    (1) | 1  1  1 |
| .  (1)  . | (1)  (1)  .   | .  .  . |
| 1  .    1 | .    .    (1) | 1  1  1 |
+-----------+---------------+---------+
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  -1   1 | 1    1    (1) | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
+-----------+---------------+---------+

now the confusion in these

is that its a Col/row + grouped link in a box

when its
its ERI + row/col

Code: Select all

 er (box + Col)
+-----------+---------------+---------+
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
+-----------+---------------+---------+
| 1  .    1 | .    .    (1) | 1  1  1 |
| .  (1)  . | (1)  (1)  .   | .  .  . |
| 1  .    1 | .    .    (1) | 1  1  1 |
+-----------+---------------+---------+
| 1  .    1 | 1    1    .   | 1  1  1 |
| 1  -1   1 | 1    1    (1) | 1  1  1 |
| 1  .    1 | 1    1    .   | 1  1  1 |
+-----------+---------------+---------+

Code: Select all

 er {box + col}
+-----------+-------------+---------+
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
+-----------+-------------+---------+
| 1  .    1 | .    .  .   | 1  1  1 |
| .  (1)  . | (1)  .  .   | .  .  . |
| 1  .    1 | .    .  (1) | 1  1  1 |
+-----------+-------------+---------+
| 1  .    1 | 1    1  .   | 1  1  1 |
| 1  (1)  1 | 1    1  -1  | 1  1  1 |
| 1  .    1 | 1    1  .   | 1  1  1 |
+-----------+-------------+---------+


hopefully from these examples you can see where people get confused on how they function.

now for more fun, both ER & 2 string kite exist at the same time using almost identical cells.


setting up the premises for the oddigon pattern for odd length strong link cases

these all work as the missing Appex * cell in the ERI is missing

Code: Select all

oddigons
+------------+---------------+---------+
| 1  .     1 | 1     1  .    | 1  1  1 |
| 1  .     1 | 1     1  .    | 1  1  1 |
| 1  .     1 | 1     1  .    | 1  1  1 |
+------------+---------------+---------+
| 1  .     1 | .     .  .    | 1  1  1 |
| .  (+1)  . | (-1)  .  .    | .  .  . |
| 1  .     1 | .     .  (+1) | 1  1  1 |
+------------+---------------+---------+
| 1  .     1 | 1     1  .    | 1  1  1 |
| 1  (-1)  1 | 1     1  (-1) | 1  1  1 |
| 1  .     1 | 1     1  .    | 1  1  1 |
+------------+---------------+---------+

grouped oddigons

Code: Select all

+------------+------------------+---------+
| 1  .     1 | 1     1     .    | 1  1  1 |
| 1  .     1 | 1     1     .    | 1  1  1 |
| 1  .     1 | 1     1     .    | 1  1  1 |
+------------+------------------+---------+
| 1  .     1 | .     .     (1)  | 1  1  1 |
| .  (+1)  . | (-1)  (-1)  .    | .  .  . |
| 1  .     1 | .     .     (1)  | 1  1  1 |
+------------+------------------+---------+
| 1  .     1 | 1     1     .    | 1  1  1 |
| 1  (-1)  1 | 1     1     (-1) | 1  1  1 |
| 1  .     1 | 1     1     .    | 1  1  1 |
+------------+------------------+---------+

[SpAce]

I don't want this discussion to center on ER details. I fully understand that the unnamed Turbot Fish is a minimal ER but I still don't want to call it that when looked at from the Turbot Fish point of view. Calling it ER in that context is like calling a Skyscraper a Siamese Sashimi X-Wing, except that the latter is actually a more accurate synonym. While both names are valid for that particular pattern of candidates, they come from different points of view: one from chaining and the other from fishing, and they should be used correspondingly in those contexts only.

ER is of course a little bit closer conceptually because it's also a chaining pattern like Turbot Fish, but its normal form centers on a group link in the hinge box, which makes it different from simple Turbot Fishes. To be accurate, we could call our unnamed Turbot a Minimal ER or Ungrouped ER, but that would be ugly. If we call it just ER, then we're losing accuracy because it's not clear whether simple or grouped links are implied. No matter what we do, it remains different from its siblings which are fully defined -- unless we give it a real name that is specific to the Turbot Fish family. That would be by far the cleanest solution in my mind. Anything else keeps the hierarchy broken one way or another.

To be honest (and I mean no disrespect to whomever invented the pattern) Empty Rectangle is a horrible pattern name anyway. It's very confusing, because it doesn't actually describe a pattern of candidates at all, but an external pattern of empty cells that can be used (quite awkwardly) to recognize a part of the real pattern. The result is that "ER" is often used incorrectly to refer to that single part which is really an ERI. A real ER is the four-node chain pattern with the hinge containing one of the two strong links, yet the name describes only the hinge part (and indirectly that too). That's why I've never liked that name at all in the first place.

There's one more problem with the minimal ER point of view. A minimal ER is actually not a well-defined ER, because there are two ERIs within the hinge box when it has only two candidates (and thus either one can be linked both horizontally and vertically). That makes things a bit more confusing as well, because the resulting Turbot Fish can have different shapes depending on how the hinge is used. A normal (grouped) ER is much more limited in what the shape can be, so it's easier to recognize as such.

[SpAce]

Eris aren't complicated minimal or maximum.

You're right, they aren't. That's why they don't need such complicated explanations, imho.

it's a conjugate link
row is true or the col regardless of number of cells.

Exactly. Yet, single candidate conjugates are simpler and easier to spot than grouped ones, and chains using the former are simpler than chains using the latter. In other words, a minimal ER is simpler than a normal ER -- but because of that it's also harder to see as an ER, which makes it an awkward point of view to describe it as such.

[StrmCkr]

Turbot Fish

except from above link
A Turbot Fish is really a chain and not a fish. For a detailed description of the various techniques and terms regarding chains please see Chains: Introduction.

A Turbot Fish is an X-Chain that is exactly four candidates long. Various shapes can be built with such a chain. One of them resembles a fish, which gave the technique its name (look at the right example: draw two lines from the red candidate to the nearest green and blue candidates to see the fish shape).

Turbot Fishes have gone a bit out of style. One of the reasons is, that most of the principle turbot patterns have been described as separate patterns with their own names: Skyscraper, 2-String Kite and Empty Rectangle (only two candidates in the empty rectangle itself).

I do find this topic an odd way of trying to tie U.F.G patterns that are named back within the short x-chain called turbots.

{yes they do happen to cross over each other but that is the nature of strong links vs cover sector. } {they both describe the same thing}

i do get you point that you would like a name for this. instead of calling it the " Turbot" as its the only one potentially left out of the named x-chain length (4) that's not named and covered with in the turbo technique.

Code: Select all

    er {box + col}
    +-----------+-------------+---------+
    | 1  .    1 | 1    1  .   | 1  1  1 |
    | 1  .    1 | 1    1  .   | 1  1  1 |
    | 1  .    1 | 1    1  .   | 1  1  1 |
    +-----------+-------------+---------+
    | 1  .    1 | .    .  .   | 1  1  1 |
    | .  (1)  . | (1)  .  .   | .  .  . |
    | 1  .    1 | .    .  (1) | 1  1  1 |
    +-----------+-------------+---------+
    | 1  .    1 | 1    1  .   | 1  1  1 |
    | 1  (1)  1 | 1    1  -1  | 1  1  1 |
    | 1  .    1 | 1    1  .   | 1  1  1 |
    +-----------+-------------+---------+

[SpAce]

Here's an ugly diagram depicting the four possible manifestations of the unnamed Turbot Fish:

Code: Select all

x               O
              //
             //
            O
            |
            |
            |
            |
O===========O


                O
              //|
             // |
x           O   |
                |
                |
                |
                |
O===============O


x           O
             \\
              \\
                O
                |
                |
                |
                |
O===============O


            O
            |\\
            | \\
x           |   O
            |
            |
            |
            |
O===========O

Based on those shapes, I think there's one obvious possibility for the name: Crane. What do you think? Then we'd have a full set of equal Turbot siblings: Skyscraper, 2-String Kite, and Crane. Since no one's suggested any alternatives, I guess I'm officially suggesting this name now.

For the grouped variant there's nothing wrong with using ER as usual. However, to keep things consistent within the family, I also suggest that the term Grouped Crane could be used as a synonym (just like Grouped Skyscraper is a synonym for Finned (Sashimi) X-Wing) if one wants to emphasize the Turbot point of view. (I'd fully expect everyone to keep using ER anyway, but logically this option must exist.)

Thus our new Turbot hierarchies would look like this:

Code: Select all

                               X-Chains                   
                                   |                     
                             Turbot Fishes               
                                   |                     
           -----------------------------------------------   
          |                        |                      |
     [Skyscraper]           [2-String Kite]            [Crane]  (<-> Minimal ER)

Code: Select all

                          Grouped X-Chains
                                   |
                         Grouped Turbot Fishes
                                   |
           -----------------------------------------------
          |                        |                      |
[Grouped Skyscraper]    [Grouped 2-String Kite]    [Grouped Crane]  (<-> Any ER)

So... how about that?

Edit: Another possibility could be "Turbot Crane" to make it clearer what family it belongs to. It would make the name a bit different from its siblings, but since it's a late-comer, the prefix might help tie it into the family. Nowadays most people seem to call the pattern simply "Turbot Fish", and "Turbot Crane" would be a short step from that (but still carry much more information by specifying the actual subtype).

[SpAce]

Turbot Fishes have gone a bit out of style. One of the reasons is, that most of the principle turbot patterns have been described as separate patterns with their own names: Skyscraper, 2-String Kite and Empty Rectangle (only two candidates in the empty rectangle itself).

That's a really bad quote from an otherwise great documentation. It's clearly wrong to say that "Turbot Fishes have gone a bit out of style"! It's like saying AICs have gone a bit out of style, if someone tags their short chains as various Wings or other more informative subtypes. Skyscrapers, Kites and Cranes (!? ) are subtypes of Turbot Fishes and not some completely separate patterns, and they're definitely not out of style. Another misleading comment starts with "most of the principle turbot patterns..." As far as I know, it should say "all of the turbot patterns..." (since he counted Empty Rectangle in as the third type). Btw, could you please mark the sources of your quotes (I added it here)?

I do find this topic an odd way of trying to tie U.F.G patterns that are named back within the short x-chain called turbots.

{yes they do happen to cross over each other but that is the nature of strong links vs cover sector. } {they both describe the same thing}

That is one weird interpretation of my points. UFG patterns have nothing to do with this. I hope you understand that you don't have to tell me that Turbot Fishes aren't really fishes? I'm very well aware of that (and also of the fact that they CAN be described using complicated UFG terms if one really wants to.) I also happen to think that the whole term Turbot Fish is a misnomer because it's a chain and not a fish POV, but I didn't bother to mention such a self-evident fact, because there's nothing we can do about it at this point.

i do get you point that you would like a name for this. instead of calling it the " Turbot" as its the only one left out of all the named x-chain length (4) that's not named and covered with in the turbo technique.

Exactly. That would complete the Turbot hierarchy so that it would actually make sense. Now it's incomplete, and as the Hodoku quote above proves, it can lead to misconceptions about the Turbot family. It's just three distinct patterns, but leaving one of them unnamed suggests there are more turbot patterns out there. There aren't, as far as I know. So I suggest we name the third one as well and close the loop.

[StrmCkr]

Code: Select all

Skyscrapers, Kites and Cranes (!? ;) ) are sub types of Turbot Fishes and not some completely separate patterns,

well to be fair, they did go out of style as turbots where short x-cycles/chains {aka simple coloring}

UFG patterns have nothing to do with this.

it does fit in my point of view as x chains where replaced with nxn fish from the u.f.g which covered all of them and more by compiling all the single digit "pattern" methods under one umbrella.

x-chains
the small sized fish of 2 sector size happened to be named, and coincided with the x-chain length 4, {ie turbots.} hence there reference to them
{you can cross check those names in the ufg listed above as they are also documented there.}


here are the other size 4 turbot not documented.

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 franken x-wing   {deleted}
+-------------+---------+---------+
| .  (1)  (1) | 1  1  1 | 1  1  1 |
| .  (1)  (1) | 1  1  1 | 1  1  1 |
| .  (1)  (1) | 1  1  1 | 1  1  1 |
+-------------+---------+---------+
| .  (1)  (1) | 1  1  1 | 1  1  1 |
| .  (1)  (1) | 1  1  1 | 1  1  1 |
| .  (1)  (1) | 1  1  1 | 1  1  1 |
+-------------+---------+---------+
| 1  -1   -1  | 1  1  1 | 1  1  1 |
| 1  -1   -1  | 1  1  1 | 1  1  1 |
| 1  -1   -1  | 1  1  1 | 1  1  1 |
+-------------+---------+---------+

or a minimal version

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 franken x-wing
+-------------+---------+---------+
| .  .    .   | 1  1  1 | 1  1  1 |
| .  (1)  .   | 1  1  1 | 1  1  1 |
| .  .    (1) | 1  1  1 | 1  1  1 |
+-------------+---------+---------+
| .  .    .   | 1  1  1 | 1  1  1 |
| .  .    (1) | 1  1  1 | 1  1  1 |
| .  (1)  .   | 1  1  1 | 1  1  1 |
+-------------+---------+---------+
| 1  -1   -1  | 1  1  1 | 1  1  1 |
| 1  -1   -1  | 1  1  1 | 1  1  1 |
| 1  -1   -1  | 1  1  1 | 1  1  1 |
+-------------+---------+---------+

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 franken x-wing {deleted}
+--------------+---------+---------+
| 1   .    .   | 1  1  1 | 1  1  1 |
| 1   .    .   | 1  1  1 | 1  1  1 |
| 1   .    .   | 1  1  1 | 1  1  1 |
+--------------+---------+---------+
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
+--------------+---------+---------+
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
| -1  (1)  (1) | 1  1  1 | 1  1  1 |
+--------------+---------+---------+


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 franken x-wing minimal
+--------------+---------+---------+
| 1   .    .   | 1  1  1 | 1  1  1 |
| 1   .    .   | 1  1  1 | 1  1  1 |
| 1   .    .   | 1  1  1 | 1  1  1 |
+--------------+---------+---------+
| -1  .    .   | 1  1  1 | 1  1  1 |
| -1  (1)  .   | 1  1  1 | 1  1  1 |
| -1  .    (1) | 1  1  1 | 1  1  1 |
+--------------+---------+---------+
| -1  .    (1) | 1  1  1 | 1  1  1 |
| -1  (1)  .   | 1  1  1 | 1  1  1 |
| -1  .    .   | 1  1  1 | 1  1  1 |
+--------------+---------+---------+

now if i happen to be mistaken on my naming time line ill go back through and retract my statements on name association but that is my memory of the events surrounding naming,

http://forum.enjoysudoku.com/post16991.html?hilit=skyscraper#p16991 patterns technically {early form of the ufg } others pointed out that they are forums of turbot-chain even back when harvard first posted it an added the side note then.

" crane" he dubbed "the real fish pattern" ie turbot ..........> hence its name in hodoku.

in the same link you'll also find the documentation for the empty rectangle creation around page 4/5, which is also pointed out as the exact same the "Hinge" rule of Rod Hagglund {and that webpage is complete lost to time}

one last note the franken class can get a bit messy as some cases of skyscrapers can land on them and they are considered both.

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+--------------+------------+------------+
| 1   .    .   | 1   1   1  | 1   1   1  |
| 1   .    .   | 1   1   1  | 1   1   1  |
| 1   .    .   | 1   1   1  | 1   1   1  |
+--------------+------------+------------+
| -1  .    .   | 1   1   1  | 1   1   1  |
| -1  (1)  .   | 1   1   1  | 1   1   1  |
| -1  .    (1) | 1   1   1  | 1   1   1  |
+--------------+------------+------------+
| -1  .    .   | 1   1   1  | 1   1   1  |
| -1  (1)  (1) | -1  -1  -1 | -1  -1  -1 |
| -1  .    .   | 1   1   1  | 1   1   1  |
+--------------+------------+------------+

[SpAce]

well to be fair, they did go out of style as turbots where short x-cycles/chains {aka simple coloring}

No. I'm repeating myself, but Turbots didn't go out of style -- the different subtypes just got more specific names, as I already explained. Yes, they're short X-Chains, as is clearly depicted in the hiearchy of my opening post: Skyscrapers, Kites, and Cranes are subtypes of Turbot Fish, which is a subtype of X-Chain, which is a subtype of AIC (not shown in my diagram). Should we start calling them simply AICs because it covers every type of chain??? We could, but I don't think it's a good idea. The more specific type you use, the more information it contains. It's a simple type hierarchy which should make perfect sense to any object-oriented programmer (like Hobiwan, which is why I'm surprised his description of Turbots was so much off). Lastly, no, X-Chains are not the same as Simple Coloring (not even close, actually, because Simple Coloring doesn't follow weak links, so it can't even produce the same eliminations.)

it does fit in my point of view as x chains where replaced with nxn fish from the ufg which covered all of them and more
x-chains

So untrue. X-Chains were never replaced with UFG fish. The latter just provided another POV for them, which happens to be much more complicated. That's why hardly anyone uses the fish POV if a simple chain is available. Just look at the daily puzzles here. How often do you see a fish-based solution??? On the other hand, various Turbot Fishes (using their specific names, when applicable) and longer X-Chains are seen quite often, either as is or in their almost-forms.

here is the other size 4 turbot not documented.

Look at my first post. I did mention both X-Wing and Franken X-Wing as Turbot Fish types (the latter as a grouped type), and said I'd chosen to omit them. I actually drew them in my first hierarchy diagrams but removed them, because I thought they added no value to the topic. I still think so.

now if i happen to be mistaken on my naming time line ill go back through and retract my statements on name association but that is my memory of the events surrounding naming,

I did my research before I made the original post. I think I have a pretty clear idea on how things got to be named the way they were, since the original discussions are still available. I also linked to them in my original post.

http://forum.enjoysudoku.com/post16991.html?hilit=skyscraper#p16991 patterns technically {early form of the ufg } others pointed out that they are forums of turbot-chain even back when harvard first posted it an added the side note then.

You're linking stuff I'd already linked to. None of this is new to me. Like I said, I did my research.

" crane" he named "the real "fish pattern" ie turbot

As I said in the original post.

..........> hence its name in hodoku.

No. It doesn't have a name in Hodoku. With default settings it's just listed as a generic Turbot Fish, together with X-Wings, Skyscrapers, and Kites. It's not its name -- it's its class. That's the problem: you can't isolate it at all as a specific named pattern like all the others. Even if you use the option of listing it as an ER (thanks for requesting that option, btw!), as I do, you'll see it together with the normal ERs.

[StrmCkr]

So untrue. X-Chains were never replaced with UFG fish. The latter just provided another POV for them, which happens to be much more complicated. That's why hardly anyone uses the fish POV if a simple chain is available. Just look at the daily puzzles here. How often do you see a fish-based solution??? On the other hand, various Turbot Fishes (using their specific names, when applicable) and longer X-Chains are seen quite often, either as is or in their almost-forms.

off topic, Fish aren't used in the daily game as simple Sudoku included simple coloring which was the "turbot" function back then which did not include ER's but covered types of "turbots"
so yes simple coloring is actually single digit pattern coloring another way of saying an x-cylce/ or x-chain.

large fish can be used to post a solution, however every large fish above size 4 usually has a complimentary smaller fish. {which usually is included in ss. } so fish are mostly avoided in the game.

technically: the only time ive seen a fish pattern posted in the daily game is when the construct submitted to play is quickly solved with just 1 of the small moves.
more often its an AIC/ niceloop of some kind.

the point i am making is that "patterns" single digit solving methods eventually became the UFG and these are not classed as chains.
{to repeat for a third time as it was clearly missed in previous posts}

..........> hence its name in hodoku.

No. It doesn't have a name in Hodoku. With default settings it's just listed as a generic Turbot Fish

the real fish aka "Turbot" {was hoping you would have noticed the latent joke}

the names skyscraper, Empty Rectangle, 2-string kite was applied to a pattern based solving method. {reference to Harvard opening words}

not specific cases of Turbots.

it was noted that they could be considered part of the Turbot chain family and Harvard added it to his opening post. which we both posted.
to me every time those names show up they aren't "turbo chains" they are actually from the U.F.G

so the mistake to me is associating those names with
Turbots which is a length 4 - x cycle which happens to make size 2 ufg fish.

[blue]

Hi SpAce,

In the spirit of "fun" ...

(...) you'll see it together with the normal ERs.

You mean "grouped" ERs ?

If you want a new name to catch on, i think you should find one with three syl-la-bles.
Two-String-Kite, Sky-scra-per ... Some-thing-else.
Tur-bot-Fish ... hmm ... I think I see a pattern

Cheers,
Blue.

[StrmCkr]

deleted