... by: Envy E
-4 G1 +4 G3Set G3 to 4 and let Solver takes steps
This leads to a unique rectangle eliminating 5 and 7 from G1
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#686, February 21 - February 27, 2026:
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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). |
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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
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Discussion...
Post an idea here...Sunday 22-Feb-2026
Set G3 to 4 and let Solver takes steps
This leads to a unique rectangle eliminating 5 and 7 from G1
Sunday 22-Feb-2026
... by: Envy E
Start from where Solver runs out of known solutions-4 D2 +4 D1 +4 G3 +1+2+7 A3 B3 C3 +5+7+9 E1 E2 F3 +2-4 D2
Sunday 22-Feb-2026
... by: Serban
# 686 A1=6 C9=J5=4 C7=9 Basics 271. C2=G4=7 solve
2. C2=7 & E1=5 solve
3. C2=7 & H3=5 solve
Saturday 21-Feb-2026
... by: Dieter
#686 - initially populated cells: 23 = 28,4 %No solver used, solver = brain.
basics: C9=J5=4; A1=6; C7=9
populated cells: 27 = 33,3 %
Strategy: numbers 4,6,8,1,9 occur most frequently, combine two cells.
combinations of D1 = (1,2,4,5,7) and D4 = (1,5,6,7)
after basic checks 1 matrix left: D1/D4 = 2/1
D1/D4 = 2/1 solves with J4=5
Optimization:
D1=2 & J4=5 solve.
Saturday 21-Feb-2026
... by: Yves
F4=8 or G6=8 or F6=9Saturday 21-Feb-2026
... by: Serban
# 686 A1=6 C9=J5=4 C7=9 Basics 271. F4=8 OR G6=8 solve
2. F6=9 OR G3=9 solve