The New Sudoku Players' Forum

[ronk]

The rules don't say that digits 1 and 3 should be opposite to each other.

RW, thanks. That was certainly the problem ... and it's an easy puzzle even without that symmetry ... especially since it didn't exist.

[gurth]

Emeralds : Valid sudokus ?

Emeralds bestride both fields: sudoku variants and non-variant sudokus. Some may be variant ( by virtue of having multiple solutions by non-emerald rules) but others may be perfectly non-variant
( by virtue of having only one solution by non-emerald rules).

However, I wish to keep both types closely together, because they obviously ARE closely linked, having identical techniques. And I wish to keep them on the General/Puzzles forum, because their special techniques are applicable, and valuable, to non-variant sudokus such as Tso's Puzzle.

But in future I will not intrude the variant ones on threads authored by others. I will confine them to threads authored by myself and by those who SPECIFICALLY invite them. That should satisfy everyone.

[gurth]

GA28Emerald

Code: Select all

  . . . 4 . . . . .
  . . 4 . 7 . . . .
  . 7 . . . 6 . . .
  9 . . 6 . . 5 . .
  4 . . 2 . . 7 3 .
  8 . . 5 . . 4 . .
  . 9 . . . 4 . . .
  . . 6 . 5 . . . .
  . . . 7 . . . . .


A nice easy Emerald, as promised.

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[gurth]

GB01 : SE 9.1

Code: Select all

  . . 8 . . 2 . . 9
  . 5 . . . . . 6 .
  3 . . 4 . . 1 . .
  . . 7 . . . . . .
  . 3 . . 4 . . 5 .
  2 . . 3 . . 7 . .
  . . 9 . . 6 . . 1
  . 6 . . 5 . . 9 .
  7 . . 8 . . 6 . .


My third niner. I've still to beat 9.1! That puts me a long way behind the champs. But nil desperandum. Maybe one day I'll learn something...

This puzzle is also a 9.1 pearl: by far my biggest so far.

An interesting thing is : change f1 to 4, and the pearl grows to 9.2, but the puzzle declines to 9.0! I think I'd rather have the 2f1. But this is really a collection of 2 puzzles, with almost equal claims.
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Udosuk, "GA06 : A Turquoise Pearl" was my second niner, rated 9.1 with Pearl 7.2, posted on this General/Puzzle forum. My first niner was G929, also 9.1, posted on the same forum, under the title "G929 : Third Pearl of September".

Other puzzles I can put my finger on now include:
(1) G910...must be on the same forum I imagine, I think it was rated 8.9.
(2) "GA01 : Present for Claudia" , rated 7.4.
(3) GA12, in the thread Gurth's Puzzles.
(4) Emerald Puzzles, posted on the same thread as (3).
(5) GA04, GA05 (rated 8.3), and GA31, and G27Emerald, all on claudiarabia's thread Rare and Original Shapes.
(6) Other puzzles posted on the Discussions forum. Do you want those too?

That's how far I've got with my catalogue so far.
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[gurth]

GB02 : My fourth niner.

Code: Select all

  2 . . . 3 . 8 . 6
  . . 4 2 . . . 1 .
  . 7 . . . . . . .
  9 . . . . 7 5 . .
  . 6 . . 8 . . 3 .
  8 . . . . . 4 . .
  . . . . . 4 . . 7
  . . . 8 . . . 2 .
  . 5 . . 6 . 9 . .


Looks a bit non-descript, and only became SE 9.0 (and Pearl 9.0) after quite a lot of alterations to the original, by dint of touching. Got the idea from you, JPF!

First it started at 8.3 with 9b4, 0e5(yes, that's nothing!), 1f5, 1g1.
Then touching, 2b4, raised this to 8.5, and also made 1g1 redundant, removing which raised to 8.9.
Finally I MOVED the 1f5 to 8e5, changing the digit during the move, to get to 9.0. I suppose that's a bit more than a touch!

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GB03 : My fifth niner : A Jade (SE 9.0)

Code: Select all

  1 . . . . . 5 . .
  . 2 . . 6 . . 7 .
  . . 3 . . 4 . . 9
  9 . . 8 . . 6 . .
  . 8 . . 7 . . 4 .
  . . 7 . . 2 . . .
  8 . . 7 . . 1 . .
  . 5 . . . . . 2 .
  . . 6 . . 8 . . 3


Jades are very sweet to you in the beginning: the very opposite of pearls. Then all of a sudden they get nasty!

Here you can start with 5 easy singles. Then suddenly and with no warning, you are thrown into the deep end! The next 5 steps have SE ratings 7.3, 7.9, 8.3, 8.4, 9.0 and you are soon out of your depth.

Or should I rather call these trollops? Do you know any of these characters?

[udosuk]

Jades are very sweet to you in the beginning: the very opposite of pearls. Then all of a sudden they get nasty!

Here you can start with 5 easy singles. Then suddenly and with no warning, you are thrown into the deep end! The next 5 steps have SE ratings 7.3, 7.9, 8.3, 8.4, 9.0 and you are soon out of your depth.

Or should I rather call these trollops? Do you know any of these characters?

Good name... There are 2 types of Jades: Jadeite & Nephrite. The Nephrite has a much softer outside than the Jadeite, but they're both precious. So your name "Jade" perfectly describe the puzzles with the "Nephrite" property: being soft outside but having toughness inside...

[gurth]

GB02A (SE 7.3)

Code: Select all

  . . 3 4 . 6 2 . .
  . . . . 5 . . 7 .
  1 . . . . . . . 3
  3 . . 5 . . . . 9
  . 4 . . 9 . . 3 .
  5 . . . . 8 . . 7
  6 . . . . . . . 2
  . 8 . . 1 . . . .
  . . 1 2 . 9 6 . .


Anybody looking for a puzzle rated SE 7.3 to solve?
I didn't think the shape quite worthy of Claudia's shapes thread.
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GB04 : Mosquito

Code: Select all

  3 . . . . 4 . . 8
  . . . . 2 . . 6 .
  . . 9 7 . . 4 . .
  . . 2 . . . 1 . .
  . 1 . . . . . 3 .
  4 . . . . . . . 6
  . . 7 9 . . 2 . .
  . 8 . . 1 . . 4 .
  9 . . . . 3 . . 5


Probably my best effort to date. SE 9.1, Pearl 9.1, Turquoise 6.7
(In case you've forgotten, the Turquoise is measured by the difficulty of removing the first candidate from the SS grid.)

Tarek's influence (empty box, diagonal clues in boxes) is discernible.

[gurth]

GB05 : Another Huge Turquoise (6.7)

Code: Select all

  . . 5 3 . . 1 . .
  . 2 . . 4 . . 9 .
  8 . . . . 9 . . 7
  1 . . . . . . . 3
  . 6 . . . . . 2 .
  . . 4 . . . 9 . .
  7 . . 6 . . 4 . .
  . 3 . . 2 . . 5 .
  . . 9 . . 1 . . 8


Many people use programs such as SS and SE to help with some or more of the chores of solving. To these people, candidates and their removal are a big reality. The first step of a difficult puzzle is usually the elimination of candidate/s, rather than the placement of a single.

So the real STARTING difficulty is the difficulty of the FIRST STEP.
THIS is the measure of the Turquoise. What it takes to break the ice.

When faced with even enormous Pearls such as those in Fluid Drives #s 1 & 2, it's usually not nearly so hard to make a start OF SOME SORT. By which I mean the elimination of candidates. You can do this in Fluid Drive #1 using a first step of SE rating 3.4.... Fluid Drive #2 can be started with a naked quad, rated even lower.

But my GB04 needed SE 6.7 for that first step, and so does this new puzzle. It then yields (eventually) a Pearl of value 7.2, which is also the overall rating of the puzzle.

What is the biggest known Turquoise? That you know of?

Note: You can transform this puzzle to something very different by changing 8k9 to 2k9. Then she becomes a Jade who sweetly starts by presenting you with 5 easy singles as an appetizer, then hardens up to an eventual SE 8.3 .

[RW]

What is the biggest known Turquoise? That you know of?

A quick look in the "hardest" thread revealed this turqoise size 9.3:

Code: Select all

26: Ocean #3/M21/D21 (9.9)
 *-----------*
 |...|..1|..2|
 |.1.|.3.|.4.|
 |5..|6..|...|
 |---+---+---|
 |..4|...|..1|
 |.7.|.8.|.3.|
 |2..|...|9..|
 |---+---+---|
 |9..|..2|...|
 |...|.4.|.7.|
 |..3|5..|8..|
 *-----------*

I didn't check all of the thread, might be some bigger turqoises there as well. I have a vague memory of seeing somewhere a 9.9 or 10.0 for the first move, but I can't recall where right now...

RW

[udosuk]

Note: You can transform this puzzle to something very different by changing 8k9 to 2k9.

Just a quick question... Sorry I'm not familiar with this "chess notation", but does "k9" mean "r9c9"? And does "k" refer to r9 or c9? Normally we'd use the letters "abcdefghi", but I can understand some would skip the "i" (to prevent confusion with "1") and use "j" instead, but if you use "k" then what other letter in "abcdefgh" was skipped? All in all, is there a thread which explains this notation in details? Thanks if anyone could point me there!

[gurth]

.
udosuk, 7k8 means r9c8=7. (3 symbols replace 6, my idea of efficiency.) Sorry I am very weak on giving links, but this "k9" notation has been very extensively used by maria45 on the Advanced Solving Methods forum.

I became an immediate convert to "k9" on first reading Maria's work. Especially because of the "k" and the small letters, because of its vastly SUPERIOR READABILITY and conciseness. I went a bit further than Maria even, replacing her k8=7 with 7k8, and k8<>7 with -7k8.

The "k" skips over the "i" AND the "j". "k" is better than "j", believe me.

RW, thanks for the info re Turquoises.

[gurth]

.
GB07 : Another niner.

Code: Select all

  . . . . . . 4 6 .
  . 8 . . 2 . . . 7
  . . 3 1 . . . . 9
  . . 7 . . . . . 4
  . 6 . . 1 . . 8 .
  4 . . 5 . . 9 . .
  1 . . . . 8 . . .
  2 . . . 6 . . 3 .
  . . 6 7 . . . . .


SE 9.0 - every day I seem to be able to produce a sudoku in the range 9.0 - 9.1, but never higher. That suggests that a radical new difficulty enters at the level of 9.2 .

The influence of JPF's latest has entered here, but it makes no difference.

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[Ocean]

Jades are very sweet to you in the beginning: the very opposite of pearls. Then all of a sudden they get nasty!

Here is a present, a reward for solving the first Anemone puzzle. It's an Extreme Jade: Five hidden singles. Then complete stop (Eliminations by Turbot Fish, further up to ER 10.4, and "stop"). Not posted before, but will probably be posted in the 'hardest' thread later.

Code: Select all

#
# "Extreme Jade puzzle (for gurth)".
# gsfr=99839 ; ER: fails.
#
 *-----------*
 |..1|..2|...|
 |.3.|.4.|.5.|
 |6..|7..|8..|
 |---+---+---|
 |..8|...|..7|
 |.1.|...|.3.|
 |9..|...|5..|
 |---+---+---|
 |..2|..1|..6|
 |.4.|.5.|.2.|
 |...|6..|9..|
 *-----------*

[gurth]

.
Ocean,
thank you for this wonderful present, your second entry into the rarified world of the super-SE sudokus! A world which now consists of 3, as far as I know.
I couldn't resist this Extreme Jade: my solution is posted on the Advanced Solution Techniques thread.
_____________________________

[gurth]

.
GB08 : "Fan1" : SE 9.0

Code: Select all

  . . 6 1 . . . . 9
  . 7 . . 2 . 8 . .
  . . 4 . . 3 . 7 .
  . . 5 . . . . . 4
  . 8 . . . . . 6 .
  9 . . . . . 2 . .
  . 1 . 7 . . 3 . .
  . . 2 . 8 . . 5 .
  6 . . . . 4 7 . .


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