... by: BGH
2 Step Solution Basics 28.43 @ B2 51.9 Solves all 3’s (Row, Column & Block Unit Pairs)
2 @ C7 100% Solves 2’s for 3 Blocks (Row, Column & Block Unit Pairs)
Dteter, Serban & Yves Solutions Match
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#667, October 11 - October 17, 2025:
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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). |
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
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Discussion...
Post an idea here...Sunday 12-Oct-2025
3 @ B2 51.9 Solves all 3’s (Row, Column & Block Unit Pairs)
2 @ C7 100% Solves 2’s for 3 Blocks (Row, Column & Block Unit Pairs)
Dteter, Serban & Yves Solutions Match
Saturday 11-Oct-2025
... by: Dieter
#667 - initially populated cells: 23 = 28,4%No solver used.
basics: %
Strategy: Numbers 2,3,5,8,9 occur most frequently, combine two cells.
combinations of A7 = (2,3,5,7) and A9 = (3,5,9)
4 matrices left after basic checks.
A7 /A9 = 3/9 solve with D8=1.
Optimization:
A7=3 & D8=1 solve.
Saturday 11-Oct-2025
... by: Serban
# 667 Basics to 231. Number 1 n=2 e=7 N=29 Nc=38 Ns=28 => E2=J5=1 solve
2. Number 7 n=2 e=7 N=26 Nc=28 Ns=15 => A8=H1=7 solve
3. A8=7 & A7=3 solve
4. A8=7 & G5=8 solve