SudokuWiki.org
Strategies for Popular Number Puzzles
Solvers
Weekly 'Unsolvable'
Puzzles to Play
Apps
Str8ts
Other
Caution!
Print Version
Page Index

#653, July 5 - July 11, 2025:
The Weekly 'Unsolvable' Sudoku Puzzle

by Andrew Stuart
WARNING: This is the Weekly 'Unsolvable' Sudoku, rated above 'Extreme'.
This is currently unsolvable by my solver, except perhaps with trial and error strategies.
Using the solver will not help you. (much).

Archive

Each week a new 'unsolvable' will be published and the previous will be accessible here from this archive section. If you like very tough puzzles, these are for you.
Share and Enjoy
Supporter Members have access to all these puzzles going back to number 1.

Discussion...

Post an idea here...
Your Name or Handle

Your suggestion, idea or question

Please enter the
letters you see:
 arrow		 Enter these letters



Please keep your comments relevant to this puzzle.
Email addresses are never displayed, but they are required to confirm your comments. To state your solve time use the smaller form at the top right of this page. Line breaks and paragraphs are automatically converted ? no need to use <p> or <br> tags.

Monday 7-Jul-2025

... by: Frans Goosens

#653

Combination 2-digits cells

D3=5 Wrong, Undo calculation
D3=9 ( B9=7 ) Solved,

Total solving time is : 59 sec.
Number of logical steps is : 695

Sunday 6-Jul-2025

... by: BGH

2 step solution after basics
1. 9 @ D3 (part of a triple of pairs in block R2C1) (Also hits the 29 pair @ D6)
2. 2 @ C1 (Clean up Block R3C1 & Column 1)
Convergence

Sunday 6-Jul-2025

... by: Serban

# 653 D2=1 D7=7 E6=6 F2=8 Basics to 28
1. Number 6 n=6 e=3 N=7 Nc=3 Ns=1 => H3=6 OR J7=6 basics to 43
---1a. B5=1 OR F4=1 solve
---2a. D6=2 solve
---3a. A8=3 OR B1=3 OR E9=3 OR F3=3 solve
---4a. J8=4 solve
---5a. any[A3,E1,B7,D8,G9]=5 solve
---6a. A5=7 solve
---7a. B4=J1=8 solve
---8a. A6=J4=9 solve

Saturday 5-Jul-2025

... by: Yves

B1=3 Solve

Saturday 5-Jul-2025

... by: Dieter

#653 - populated cells = 24 = 29,6%
basics: D2=1; E6=6; D7=7; F2=8
populated cells = 28 = 34,6%
combinations of A3 = (3,5,6,7) and G3 = (1,2,7) as numbers 6,1,2,7 are populated most.
No solver used: A3=5 & G3=1 solves.

Saturday 5-Jul-2025

... by: Serban

# 653 D2=1 D7=7 E6=6 F2=8 Basics to 28

1. Number 4 n=2 e=7 N=30 Nc=58 Ns=4 => J8=C1=4 OR J8=G2=4 basics to 41
1a.W-wing 79 [J4,A5] => H5<>9 => H5=2 solve

2. Number 5 n=2 e=7 N=19 Nc=10 Ns=7 => A3=C4=5 OR A3=B7=5 solve
Note : J5=5
Page created on 03-May-2011, last modified on 30-May-2024.
All puzzles on this site are trademarked and copyright
and cannot be reproduced without permission.
Copyright Andrew Stuart @ Syndicated Puzzles, Privacy, 2007-2025