The New Sudoku Players' Forum

[shye]

Code: Select all

+-------+-------+-------+
| 8 . 1 | 2 3 . | . 9 . |
| . 7 . | . . . | . . 8 |
| 6 . . | . 8 4 | . . . |
+-------+-------+-------+
| 9 . . | . . . | 5 . . |
| 5 2 . | 4 . . | 9 . 3 |
| . . . | . 5 . | . . 2 |
+-------+-------+-------+
| . . 3 | . . . | . . 1 |
| 7 . . | . 2 . | . 6 . |
| . 6 . | . 4 8 | 7 . . |
+-------+-------+-------+
8.123..9..7......86...84...9.....5..52.4..9.3....5...2..3.....17...2..6..6..487..

estimated rating: 9.0
i wanted to implement the ideas from recent posts on the variants board into classic sudoku, has this been explored before? `･ω･´

[yzfwsf]

My guess is：
If r9c9=9 is a clue, then the puzzle has the diagonal（/） symmetry property and the candidate number 123 corresponds to itself, and in this way r1c9 has no solution, so r9c9=5.bte

[eleven]

Nice idea ! Here's another one, ER 8.9.

Code: Select all

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

[jovi_al01]

Nice idea ! Here's another one, ER 8.9.

Shye, your puzzle was super nice.
Eleven, yours was too. This idea is super exciting to me!

[shye]

My guess is：
If r9c9=9 is a clue, then the puzzle has the diagonal（/） symmetry property and the candidate number 123 corresponds to itself, and in this way r1c9 has no solution, so r9c9=5.bte

yes, this was what i was aiming for no symmetrical solution to the puzzle exists so for it to be unique the givens must not form that symmetry

Nice idea ! Here's another one, ER 8.9.

Code: Select all

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

this is a gorgeous extension! while symmetrical solutions might theoretically exist here, there would be no way to tell which of the 12 it is, so to be unique it must be asymmetric so -3r7c9 btte
you could also disprove it using the 19 pair gained in r6 being outside of the sticks (or 46 pair being inside)

Shye, your puzzle was super nice.
Eleven, yours was too. This idea is super exciting to me!

thank you! im really curious to see what else could be done with it now

[shye]

i wanted to make a puzzle where the deduction mentioned above was more potent, and came up with this!

Code: Select all

+-------+-------+-------+
| 8 . 4 | . 3 . | 7 . . |
| . 9 . | . . . | . 3 . |
| 1 . . | . 9 . | . . 4 |
+-------+-------+-------+
| . . 7 | . . . | 5 . . |
| . 8 . | . . . | . 2 . |
| 5 . . | . . . | . . 1 |
+-------+-------+-------+
| . . 8 | 1 2 3 | 9 . . |
| . 2 . | 4 5 6 | . 8 . |
| 3 . . | 7 8 9 | . . 2 |
+-------+-------+-------+
8.4.3.7...9.....3.1...9...4..7...5...8.....2.5.......1..81239...2.456.8.3..789..2

estimated rating: 9.0

[eleven]

Code: Select all

+-------------------------+-------------------------+-------------------------+
| 8       56      4       | 256     3       125     | 7       1569    569     |
|b267     9       256     | 2568   c1467   c124578  |d1268    3       568     |
| 1       3567    2356    | 2568    9       2578    | 268     56      4       |
+-------------------------+-------------------------+-------------------------+
| 2469    1346    7       | 23689   146     1248    | 5       469     3689    |
| 469     8       1369    | 3569    1467    1457    | 346     2       3679    |
| 5       346     2369    | 23689   467     2478    | 3468    4679    1       |
+-------------------------+-------------------------+-------------------------+
| 467     4567    8       | 1       2       3       | 9       4567    567     |
|a79      2      a19      | 4       5       6       | 13      8       37      |
| 3       1456    156     | 7       8       9       | 146     1456    2       |
+-------------------------+-------------------------+-------------------------+

This puzzle is clearly overrated by ER, because the Explainer does not see this chain, (1=97)r8c31 - 7r2c1 = (47-1)r2c56 = 1r2c7 => -1r8c7, which lowers the ER to 7.1.
But after using it, you were not able anymore to see the almost symmetry, which solves it with singles. So adding the 9 numbers you get from the chain would make it harder

[shye]

This puzzle is clearly overrated by ER, because the Explainer does not see this chain, (1=97)r8c31 - 7r2c1 = (47-1)r2c56 = 1r2c7 => -1r8c7, which lowers the ER to 7.1.
But after using it, you were not able anymore to see the almost symmetry, which solves it with singles. So adding the 9 numbers you get from the chain would make it harder

the high rating surprised me also, as it can be solved without uniqueness in two fairly reasonable steps. but yes, the symmetry avoidance is supposed to be more appealing