Nov 11 - Super Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R1C9 can only be <8>
R1C1 can only be <4>
R2C8 can only be <6>
R5C5 is the only square in row 5 that can be <4>
R5C7 is the only square in row 5 that can be <7>
R5C8 is the only square in row 5 that can be <9>
R7C8 is the only square in column 8 that can be <8>
R6C7 is the only square in column 7 that can be <8>
Squares R3C4 and R3C6 in row 3 form a simple naked pair. These 2 squares both contain the 2 possibilities <16>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R3C5 - removing <16> from <15678> leaving <578>
R3C7 - removing <1> from <12349> leaving <2349>
R3C8 - removing <1> from <14> leaving <4>
R8C8 can only be <1>
R1C7 is the only square in column 7 that can be <1>
R1C5 can only be <7>
R1C3 can only be <9>
R3C7 is the only square in row 3 that can be <9>
R9C5 is the only square in row 9 that can be <9>
R7C2 is the only square in row 7 that can be <9>
R7C3 is the only square in row 7 that can be <7>
R3C2 is the only square in row 3 that can be <7>
R7C7 is the only square in row 7 that can be <4>
R8C3 is the only square in row 8 that can be <4>
R9C3 is the only square in row 9 that can be <1>
R9C1 is the only square in row 9 that can be <8>
R7C5 is the only square in column 5 that can be <1>
Squares R9C7 and R9C9 in block 9 form a simple naked pair. These 2 squares both contain the 2 possibilities <36>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R7C9 - removing <36> from <2356> leaving <25>
R8C7 - removing <3> from <235> leaving <25>
Intersection of column 5 with block 5. The value <6> only appears in one or more of squares R4C5, R5C5 and R6C5 of column 5. These squares are the ones that intersect with block 5. Thus, the other (non-intersecting) squares of block 5 cannot contain this value.
R5C4 - removing <6> from <126> leaving <12>
R5C6 - removing <6> from <136> leaving <13>
Squares R2C3 and R2C7 in row 2, R6C3 and R6C5 in row 6 and R8C5 and R8C7 in row 8 form a Swordfish pattern on possibility <2>. All other instances of this possibility in columns 3, 5 and 7 can be removed.
R3C3 - removing <2> from <2358> leaving <358>
R5C3 - removing <2> from <23568> leaving <3568>
Squares R7C9 (XY), R3C9 (XZ) and R7C1 (YZ) form an XY-Wing pattern on <3>. All squares that are buddies of both the XZ and YZ squares cannot be <3>.
R3C1 - removing <3> from <235> leaving <25>
Squares R5C1 and R7C1 in column 1 and R5C6 and R7C6 in column 6 form a Simple X-Wing pattern on possibility <3>. All other instances of this possibility in rows 5 and 7 can be removed.
R5C2 - removing <3> from <358> leaving <58>
R5C3 - removing <3> from <3568> leaving <568>
Squares R5C2<58>, R5C3<568> and R5C9<56> in row 5 form a comprehensive naked triplet. These 3 squares can only contain the 3 possibilities <568>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R5C1 - removing <5> from <235> leaving <23>
Squares R8C7 (XY), R2C7 (XZ) and R8C2 (YZ) form an XY-Wing pattern on <3>. All squares that are buddies of both the XZ and YZ squares cannot be <3>.
R2C2 - removing <3> from <358> leaving <58>
R8C2 is the only square in column 2 that can be <3>
R8C5 can only be <2>
R7C1 can only be <5>
R8C7 can only be <5>
R6C5 can only be <6>
R7C4 can only be <6>
R4C7 can only be <6>
R7C9 can only be <2>
R4C5 can only be <3>
R9C7 can only be <3>
R5C9 can only be <5>
R5C2 can only be <8>
R6C3 can only be <2>
R3C1 can only be <2>
R7C6 can only be <3>
R3C4 can only be <1>
R5C6 can only be <1>
R3C9 can only be <3>
R9C9 can only be <6>
R2C7 can only be <2>
R5C1 can only be <3>
R3C6 can only be <6>
R5C4 can only be <2>
R4C3 can only be <5>
R5C3 can only be <6>
R2C2 can only be <5>
R2C5 can only be <8>
R3C3 can only be <8>
R2C3 can only be <3>
R3C5 can only be <5>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode option – I recommend not using your browser's dark mode or extensions for BrainBashers