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This interesting Classic Sudoku (6x6) puzzle can be solved in three steps.
(puzzle found with Sukaku 6x6Explainer)
After basics, the configuration is as follows.
,-----------------------------------,
6 | 2 *16 3 | 156 15 4 |
5 |*16 4 5 | 2 3 *16 |
|----------------+------------------|
4 | 1456 2 146 | 1456 145 3 |
3 | 3 *(5)16 146 | 1456 1245 *(2)16 |
|----------------+------------------|
2 | 14 3 2 | 14 6 5 |
1 | 1456 156 146 | 3 124 12 |
'-----------------------------------'
a b c d e f
As usual, many ways are possible.
The strong link (5)b3=(2)f3 is nice
(internal guardians of the bivalued oddagon *(16))
and leads to placements: +5 b3, +5 a1 (how ?)
Move 2 is a simple skyscraper and move 3 is similar (same idea) to move 1.
I propose the following 6x6 Classic Sudoku puzzle.
(puzzle found with Sukaku 6x6Explainer)
After no basics, the configuration is as follows.
+----------------+----------------+
| 26 3 24 | 2456 2456 1 | 6
| 5 126 124 | 3 246 46 | 5
+----------------+----------------+
| 23 25 6 | 45 1 345 | 4
| 13 4 15 | 56 356 2 | 3
+----------------+----------------+
| 126 1256 3 | 2456 2456 456 | 2
| 4 256 25 | 1 2356 356 | 1
+----------------+----------------+
a b c d e f
Update (March 18, 2025)
+----------------+----------------+
| 26 3 24 | 2456 2456 1 | 6
| 5 126 124 | 3 246 46 | 5
+----------------+----------------+
| 23 25 6 | 45 1 345 | 4
| 13 4 15 | 56 356 2 | 3
+----------------+----------------+
| 16-2 1256 3 | 2456 2456 456 | 2
| 4 256 25 | 1 2356 356 | 1
+----------------+----------------+
a b c d e f
For step 1: (2)a2 is easily shown to be false, using (1)a2=(1)a3.
For step 2: there is an almost turbot fish on 6 using cells f2,f5,b5,a6
that eliminates (6)a2, solving the puzzle.
I expected to solve the following puzzle very quickly,
but only after some effort a path was found in three steps.
(generated and displayed with Sudoku6Explainer)
After performing basic moves:
+-------------------+-------------------+
| 4 156 3 | 125 16 26 | 6
| 156 2 16 | 135 1346 346 | 5
+-------------------+-------------------+
| 26 46 5 | 23 34 1 | 4
| 3 14 124 | 6 5 24 | 3
+-------------------+-------------------+
| 156 13456 146 | 13 2 36 | 2
| 126 136 126 | 4 136 5 | 1
+-------------------+-------------------+
a b c d e f Classic Sudoku
(Update: Sept 30, 2025)
+-------------------+-------------------+
| 4 156 3 | 125 16 26 | 6
| 156 2 16 | 135 1346 346 | 5
+-------------------+-------------------+
| 26 46 5 | 23 34 1 | 4
| 3 14 124 | 6 5 24 | 3
+-------------------+-------------------+
| 156 13456 146 | 13 2 36 | 2
| 126 136 126 | 4 16-3 5 | 1
+-------------------+-------------------+
a b c d e f Classic Sudoku
I could not find a one-stepper for this one.
My first step was a M-wing that removes (3)e1.
Update (Oct 2, 2025)
+----------------+----------------+
| 4 156 3 | 125 1-6 26 |
| 156 2 16 | 135 34 346 |
+----------------+----------------+
| 26 46 5 | 23 34 1 |
| 3 14 124 | 6 5 24 |
+----------------+----------------+
| 156 1456 146 | 13 2 36 |
| 126 3 126 | 4 16 5 |
+----------------+----------------+
a b c d e f Classic Sudoku
My second step is an almost Kite that
eliminates (6)e6, nearly finishing the puzzle:
Update (Oct 3, 2025)
+----------------+----------------+
| 4 *156 3 | 125 1-6 [26]. |
| 156 2 16 | 135 34 346| |
+----------------+--------------^-+
| 26 [46]--5----|-23->[4]3 1 | |
| 3 14 124 | 6 5 [24] |
+----------------+----------------+
| 156 *1456 146 | 13 2 *36 |
| 126 3 126 | 4 *16 5 |
+----------------+----------------+
a b c d e f Classic Sudoku
So, for step 2, either we have a Kite(6) e1-f2-b2-b6, or
(6)b4->(4)e4->(2)f3->(6)f6
+--------------+-------------+
| 4 56 3 | 25 1 26 |
| 156 2 16 | 35 34 46 |
+--------------+-------------+
| 26 46 5 | 23 34 1 |
| 3 1 24 | 6 5 24 |
+--------------+-------------+
| 56 456 46 | 1 2 3 |
| 12 3 12 | 4 6 5 |
+--------------+-------------+
a b c d e f Classic Sudoku
For step 3, there are two easy ways to finish: Y-wing, or BUG+2.
This puzzle does not seem easy to solve very quickly.
I needed 4 steps, but perhaps with more analysis one can find a shortcut.
(generated and displayed with Sudoku6Explainer)
After performing basic moves:
+----------------+----------------+
| 35 4 125 | 126 123 136 | 6
| 6 23 12 | 124 5 134 | 5
+----------------+----------------+
| 1 23 246 | 2456 234 3456 | 4
| 34 5 246 | 1246 1234 1346 | 3
+----------------+----------------+
| 45 6 3 | 145 14 2 | 2
| 2 1 45 | 3 6 45 | 1
+----------------+----------------+
a b c d e f Classic Sudoku
Update (Oct 5, 2025)
+----------------+----------------+
| 35 4 125 | 126 123 136 | 6
| 6 23 12 | 124 5 13-4 | 5
+----------------+----------------+
| 1 23 246 | 2456 234 3456 | 4
| 34 5 246 | 1246 1234 16-34| 3
+----------------+----------------+
| 45 6 3 | 145 14 2 | 2
| 2 1 45 | 3 6 45 | 1
+----------------+----------------+
a b c d e f Classic Sudoku
My initial step eliminates (4)f3 [single digit pattern].
My second move eliminates (3)f3 and (4)f5 with a chain
with 4 strong links.
+----------------+----------------+
| 35 4 125 | 126 12 136 | 6
| 6 23 12 | 4 5 13 | 5
+----------------+----------------+
| 1 23 246 | 5-26 234 45 | 4
| 34 5 246 | 126 1234 16 | 3
+----------------+----------------+
| 45 6 3 | 15 14 2 | 2
| 2 1 45 | 3 6 45 | 1
+----------------+----------------+
a b c d e f Classic Sudoku
My third step removes (2)d4 and my fourth removes (6)d4.
I could combine them in a single step, using a double kraken
to remove (5)c1.
EDIT: corrected last statement [on solution in 3 steps].
I have solved (manually) the following interesting puzzle in 4 steps.
Probably there is a shorter way to be found after further analysis.
(generated and displayed with Sudoku6Explainer)
After performing basic moves:
+----------------+----------------+
| 26 4 5 | 1 3 26 |
| 3 126 12 | 24 5 246 |
+----------------+----------------+
| 1 235 234 | 6 24 245 |
| 245 25 6 | 245 1 3 |
+----------------+----------------+
| 2456 2356 234 | 245 24 1 |
| 245 125 124 | 3 6 245 |
+----------------+----------------+
CS
Update (Oct 14, 2025)
+----------------+----------------+
| 26 4 5 | 1 3 26 | 6
| 3 126 12 | 24 5 246 | 5
+----------------+----------------+
| 1 235 234 | 6 24 245 | 4
| 245 25 6 | 245 1 3 | 3
+----------------+----------------+
| 2456 2356 234 | 245 24 1 | 2
| 245 12-5 124 | 3 6 245 | 1
+----------------+----------------+
a b c d e f CS
Step 1: A chain with 5 strong links removes (5)b1 and so
+----------------+----------------+
| 26 4 5 | 1 3 26 | 6
| 3 126 12 | 24 5 246 | 5
+----------------+----------------+
| 1 235 234 | 6 24 245 | 4
| 245 25 6 | 245 1 3 | 3
+----------------+----------------+
| 2456 2356 234 | 245 24 1 | 2
| 245 12 124 | 3 6 245 | 1
+----------------+----------------+
a b c d e f CS
Update (Oct 15, 2025)
+----------------+----------------+
| 26 4 5 | 1 3 26 | 6
| 3 126 12 | 24 5 246 | 5
+----------------+----------------+
| 1 235 234 | 6 24 245 | 4
| 245 25 6 | 245 1 3 | 3
+----------------+----------------+
| 2456 2356 234 | 245 24 1 | 2
| 5-24 12 124 | 3 6 245 | 1
+----------------+----------------+
a b c d e f CS
Now, a single move eliminate (2)a1 and (4)a1 [followed by 3 placements].
Which move ? After this move, a simple fish solves the puzzle.
How to solve the following 6x6 classic sodoku puzzle in a few steps ?
(generated and displayed with Sudoku6Explainer)
,---------------------------------,
| 123 36 126 | 146 34 5 | 6
| 135 4 156 | 16 2 136 | 5
|----------------+----------------|
| 4 1 26 | 3 5 26 | 4
| 25 56 3 | 26 1 4 | 3
|----------------+----------------|
| 135 2 145 | 145 6 13 | 2
| 6 35 145 | 1245 34 123 | 1
'---------------------------------'
a b c d e f CS
Update (Jan 19, 2026)
This puzzle is solvable with just one kraken move.
Aiming for a krakenless way, there is wing that
eliminates (5)a2, creating a NP(13) at row 2.
After the NP elimination we get
,---------------------------------,
| 123 36 126 | 146 34 5 | 6
| 135 4 156 | 16 2 136 | 5
|----------------+----------------|
| 4 1 26 | 3 5 26 | 4
| 25 56 3 | 26 1 4 | 3
|----------------+----------------|
| 13 2 45 | 45 6 13 | 2
| 6 35 145 | 1245 34 123 | 1
'---------------------------------'
a b c d e f CS
How to finish this puzzle ?
Update (Jan 20, 2026)
So, move 1 had a M-wing on 2,5.
Now the digit 6 comes into play.
We can eliminate (6)f5 using the
als hub (156)c5.d5. This solves the
puzzle with singles to the end.
One Kraken that solves the puzzle
in one step eliminates directly (6)f5.
The chain for move 2 is spoiled by (5)a2,
removed by the M-wing in move 1. ///
The following 6x6 tough Classic Sudoku has a pretty solution in two steps.
(generated and displayed with Sudoku6Explainer)
,---------------------------------,
| 5 6 123 | 23 13 4 | 6
| 24 34 1234 | 6 135 235 | 5
|----------------+----------------|
| 146 134 5 | 34 2 36 | 4
| 46 2 34 | 1 345 356 | 3
|----------------+----------------|
| 124 145 6 | 2345 34 23 | 2
| 3 45 24 | 245 6 1 | 1
'---------------------------------'
a b c d e f CS
Update (Jan 20, 2026)
There is an easy to spot almost W-wing
that eliminates (2)c6, reducing the
puzzle to
,---------------------------,
| 5 6 13 | 2 13 4 | 6
| 2 34 134 | 6 135 35 | 5
|-------------+-------------|
| 146 134 5 | 34 2 36 | 4
| 46 2 34 | 1 345 356 | 3
|-------------+-------------|
| 14 145 6 | 345 34 2 | 2
| 3 45 2 | 45 6 1 | 1
'-------------+-------------'
a b c d e f
How to finish this puzzle ?
Update (Jan 21, 2026)
A W-wing is available to eliminate
(4)e3, solving the puzzle.///
ADDED: Move 1 (almost W-wing)
can be viewed as
,---------------------------------,
| 5 6 123 | 23 13 4 | 6
|*24 (4)3 1234 | 6 135 235 | 5
|----------------+----------------|
| 146 (4)13 5 | 34 2 36 | 4
| 46 2 34 | 1 345 356 | 3
|----------------+----------------|
| 124 (4)15 6 | 2345 34 23 | 2
| 3 (4)5 *24 | 245 6 1 | 1
'---------------------------------'
a b c d e f CS
Kraken column (4)b12,b4,b5 => -2 c6.
(4)b12 - (4=2)c1
(4)b4 - (4=32)d4.d6
(4)b5 - (4=2)a5
[spotted due to cells with *: W-wing]