The New Sudoku Players' Forum

[ronk]

Code: Select all

 . . . . 3 . . . .
 . 4 . . 7 . . 1 .
 . . 8 5 . 1 2 . .
 . . 3 . . . 4 . .
 7 9 . . . . . 8 1
 . . 1 . . . 9 . .
 . . 9 3 . 8 5 . .
 . 2 . . 4 . . 6 .
 . . . . 5 . . . . #SE=9.1, GSF=21368

[ravel]

Nice puzzle with an interesting nishio at the beginning (lowers ER to 8.9):

Code: Select all

 6 6 6 | 6 . 6 | 6 . 6
 6 . 6 | 6 . 6 | 6 . 6
 6 6 . | . 6 . | . . 6
-----------------------
 6 6 . | 6 6 6 | . . 6
 . . 6 | 6 6 6 | 6 . .
 6 6 . | 6 6 6 | . . 6
-----------------------
 6 6 . | . 6 . | . . .
 . . . | . . . | . 6 .
 6 6 6 | 6 . 6 | . . .


r5c5=6 => r3c5<>6
r5c5=6 (=> r5c3<>6) => r7c5<>6 => r7c12=6 => r9c3<>6 => r12c3=6
r5c5=6 => r5c7<>6 => r12c7=6
X-wing => r12c46<>6, no 6 for box 2
[Edit: corrected typo]

Any fish for that ?

[RW]

Any fish for that ?

Yes, finned Jellyfish:

Code: Select all

 6 6*6 |*6 .*6 |*6 . 6
 6 .*6 |*6 .*6 |*6 . 6
 6 6 . | . 6 . | . . 6
-----------------------
 6 6 . |#6 6#6 | . . 6
 . .*6 |*6-6*6 |*6 . .
 6 6 . |#6 6#6 | . . 6
-----------------------
 6 6 . | . 6 . | . . .
 . . . | . . . | . 6 .
 6 6*6 |*6 .*6 | . . .

With four fins and only one missing candidate, it's probably the most vicious Jelly I've ever seen.

RW

[tarek]

It is a big Jelly no doubt about it.......

It can also be constructed in rows

Code: Select all

*--------------------------------------------------------------------------*
| 12569   1567    2567   | 24689   3       2469   | 678     579     56789  |
| 23569   4       256    | 2689    7       269    | 368     1       35689  |
|*369    *367     8      | 5      *69      1      | 2       3479   *34679  |
|------------------------+------------------------+------------------------|
|*2568   *568     3      |#12679  *12689  #25679  | 4       257    *2567   |
| 7       9       2456   | 246    -26      23456  | 36      8       1      |
| 24568  *568     1      |#2467   *268    #234567 | 9       2357   *23567  |
|------------------------+------------------------+------------------------|
|*146    *167     9      | 3      *126     8      | 5       247    *247    |
| 1358    2       57     | 179     4       79     | 1378    6       3789   |
| 13468   13678   467    | 12679   5       2679   | 1378    23479   234789 |
*--------------------------------------------------------------------------*

tarek

[RW]

Nice puzzle with an interesting nishio at the beginning (lowers ER to 8.9):

This gives an interesting twist to the Explainer ratings. Because the elimination as a Nishio contradiction requires locked candidates, Explainer doesn't look for it until it has searched all forcing chains that don't require more than singles, in this puzzle 68 chains, up to ER 9.5. After all these are found, it quickly finds this as a "dynamic contradiction forcing chain+", ER 9.3. So there might be a puzzle rated 9.5, that a skilled fisherman can crack with a single fish... I'd love to see that puzzle!

RW

[tarek]

This is a flaw in Explainer's logic........

All Colouring, multiple colouring, Finned fish, Nishio should disappear into "X-cycle" with variable difficulties.

tarek

[wapati]

Explainer also over values Turbots, to my thinking.

A puzzle, simple but for one Turbot, will be rated 6.6.

That means that it is listed as a forcing chain, the only fish so designated.

[Ocean]

So there might be a puzzle rated 9.5, that a skilled fisherman can crack with a single fish... I'd love to see that puzzle!

RW

Here is a fishing pool: A puzzle with Explainer rating ER 9.5, but it contains several alternative shorter "Dynamic Forcing Chains(+)", ER 9.4:

Code: Select all

 *-----------*
 |..1|...|2..|
 |.3.|...|.4.|
 |5..|.3.|..6|
 |---+---+---|
 |4..|...|..5|
 |.5.|.6.|.3.|
 |..8|...|1..|
 |---+---+---|
 |...|1.2|...|
 |...|8.9|...|
 |.7.|.4.|.5.|
 *-----------*

Better somebody else go fishing - I'm no fisherman. Obviously, I don't even know if there is anything in it that can be called a fish.

[RW]

Here is a fishing pool

After a skinny finned Swordfish, sudocue moves directly to tabling (29 forcing chains). Sudocue would find all possible fishes before tabling at the templates check, so there is no more fish... Unless of course you are willing to dive very deep into this dark pool to search for the mythological seamonsters... Multidigit Fish!

RW

[claudiarabia]

Code: Select all

 . . . . 3 . . . .
 . 4 . . 7 . . 1 .
 . . 8 5 . 1 2 . .
 . . 3 . . . 4 . .
 7 9 . . . . . 8 1
 . . 1 . . . 9 . .
 . . 9 3 . 8 5 . .
 . 2 . . 4 . . 6 .
 . . . . 5 . . . . #SE=9.1, GSF=21368

Whow! It is untouchable! Ronk deserves a medal of honour and that is just how the sudoku looks like.

below is a version not too difficult with a some x-wings and xy-wing SE-Rating 7-1

Code: Select all

....3....
.4..7..1.
..85.12..
..3...4..
79..2..86
..1...9..
..93.85..
.2..1..6.
....9....


[ronk]

Whow! It is untouchable! Ronk deserves a medal of honour and that is just how the sudoku looks like.

Glad you like it. Consider it a belated birthday present ... an arabian star for claudiarabia.

And thanks for the mutation of that puzzle. How do you go about doing that?

[claudiarabia]

And thanks for the mutation of that puzzle. How do you go about doing that?

I'm just exchange one number in the Sudoku Explainer and look that it won't cause to much damage to the puzzle. Then I look for another number in the puzzle which will repair the rest. Sometimes it will take three numbers or more. It's just trial and error.

Claudia

[daj95376]

Code: Select all

 . . . . 3 . . . .
 . 4 . . 7 . . 1 .
 . . 8 5 . 1 2 . .
 . . 3 . . . 4 . .
 7 9 . . . . . 8 1
 . . 1 . . . 9 . .
 . . 9 3 . 8 5 . .
 . 2 . . 4 . . 6 .
 . . . . 5 . . . . #SE=9.1, GSF=21368

Nice puzzle!

Code: Select all

# after 2x Locked Candidates (1)

# finned Jellyfish in [c3467] on <6> (already presented)
# finned Jellyfish in [r3467] on <6> (already presented -- not shown)
 *-----------------------------------------------------------------------------*
 | 12569   1567   *2567    |*24689   3      *2469    |*678     579     56789   |
 | 23569   4      *256     |*2689    7       269     | 368     1       35689   |
 | 369     367     8       | 5       69      1       | 2       3479    34679   |
 |-------------------------+-------------------------+-------------------------|
 | 2568    568     3       |#12679   12689  #25679   | 4       257     2567    |
 | 7       9      *2456    |#246    -26     #23456   |*36      8       1       |
 | 24568   568     1       |#2467    268    #234567  | 9       2357    23567   |
 |-------------------------+-------------------------+-------------------------|
 | 146     167     9       | 3       126     8       | 5       247     247     |
 | 1358    2       57      | 179     4       79      | 1378    6       3789    |
 | 13468   13678  *467     |*12679   5      *2679    | 1378    23479   234789  |
 *-----------------------------------------------------------------------------*

# Franken/??? Jellyfish in [r3467] on <7> (not mentioned)
# Franken/??? Jellyfish in [c3467] on <7> (not mentioned -- not shown)
 *-----------------------------------------------------------------------------*
 | 12569  -1567    2567    | 24689   3       2469    | 678    -579    -56789   |
 | 23569   4       256     | 2689    7       269     | 368     1       35689   |
 | 369    *367     8       | 5       69      1       | 2      *3479   *34679   |
 |-------------------------+-------------------------+-------------------------|
 | 2568   *568     3       |#12679   12689  *25679   | 4      *257    *2567    |
 | 7       9       2456    | 246     26      23456   | 36      8       1       |
 | 24568   568     1       |#2467    268    *234567  | 9      *2357   *23567   |
 |-------------------------+-------------------------+-------------------------|
 | 146    *167     9       | 3       126     8       | 5      *247    *247     |
 | 1358    2       57      | 179     4       79      | 1378    6      -3789    |
 | 13468  -13678   467     | 12679   5       2679    | 1378   -23479  -234789  |
 *-----------------------------------------------------------------------------*


If either <7> fin cell is true, then Jellyfish degenerates into a Swordfish with common eliminations.

What are the odds of two overlapping and distinct Jellyfish in the same rows/columns at the same time?

[gurth]

GA05 : Open Hat and Head

Code: Select all

  . . 8 6 . . . 2 .
  . 1 . . 9 . 4 . .
  5 . . . . 7 . . .
  6 . . . . 3 . . .
  . 4 . . . . . . .
  . . 2 5 . . 9 1 .
  . 6 . . . 8 . . 3
  7 . . . . 9 . . 6
  . . . . . . 2 4 .      (SE 8.3)(Pearl 7.4)


Open hat as promised. Note the head will just fit nicely into the hat.
It's a Large Pearl : you can't get the first cell with SSTS only. (In fact you need SE 7.4 technique).

PS: For another open hat and head, see GA25Emerald, in the thread Gurth's Puzzles, posted today.

[claudiarabia]

Here's a non-minimal full-symmetry (I think) "arabian star of 25-clues" and a 7.2 SE rating.

Code: Select all

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


Let me make a humble contribution to the theme "non-minimal full-symmetry with special regard of the Arabian-Star-pattern". ;-) SE-rating 2.0

Code: Select all

 *-----------------*
 |9 . . . . . . . 3|
 |. . . . 6 . . . .|
 |. . 2 7 . 5 4 . .|
 |. . 7 . . . 1 . .|
 |. 9 . . 2 . . 8 .|
 |. . 5 . . . 6 . .|
 |. . 6 4 . 7 5 . .|
 |. . . . 8 . . . .|
 |3 . . . . . . . 2|
 *-----------------*

Claudia