May 20 - Super Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R8C5 can only be <2>
R1C1 is the only square in row 1 that can be <1>
R1C3 is the only square in row 1 that can be <2>
R2C7 is the only square in row 2 that can be <7>
R3C9 can only be <8>
R3C8 is the only square in row 3 that can be <5>
R5C8 can only be <2>
R3C1 is the only square in row 3 that can be <7>
R4C5 is the only square in row 4 that can be <1>
R4C4 is the only square in row 4 that can be <9>
R4C6 is the only square in row 4 that can be <2>
R3C6 can only be <6>
R3C2 can only be <3>
R3C4 can only be <2>
R5C5 is the only square in row 5 that can be <7>
R9C1 is the only square in row 9 that can be <2>
R9C9 is the only square in row 9 that can be <7>
Squares R1C5 and R2C5 in column 5 form a simple naked pair. These 2 squares both contain the 2 possibilities <39>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R6C5 - removing <3> from <356> leaving <56>
Intersection of row 8 with block 7. The value <4> only appears in one or more of squares R8C1, R8C2 and R8C3 of row 8. These squares are the ones that intersect with block 7. Thus, the other (non-intersecting) squares of block 7 cannot contain this value.
R7C2 - removing <4> from <14> leaving <1>
R8C8 is the only square in row 8 that can be <1>
Squares R5C1 and R5C6 in row 5 and R7C1 and R7C6 in row 7 form a Simple X-Wing pattern on possibility <5>. All other instances of this possibility in columns 1 and 6 can be removed.
R6C6 - removing <5> from <458> leaving <48>
Squares R4C3 (XY), R9C3 (XZ) and R5C2 (YZ) form an XY-Wing pattern on <8>. All squares that are buddies of both the XZ and YZ squares cannot be <8>.
R8C2 - removing <8> from <48> leaving <4>
R6C3 - removing <8> from <3568> leaving <356>
R2C2 can only be <6>
R2C3 can only be <4>
R5C2 can only be <8>
R6C6 is the only square in row 6 that can be <8>
Squares R5C4 and R5C9 in row 5 and R7C4 and R7C9 in row 7 form a Simple X-Wing pattern on possibility <6>. All other instances of this possibility in columns 4 and 9 can be removed.
R6C4 - removing <6> from <346> leaving <34>
Squares R5C6 (XY), R5C9 (XZ) and R6C5 (YZ) form an XY-Wing pattern on <6>. All squares that are buddies of both the XZ and YZ squares cannot be <6>.
R6C7 - removing <6> from <456> leaving <45>
R5C4 - removing <6> from <346> leaving <34>
R5C9 is the only square in row 5 that can be <6>
R7C9 can only be <9>
R4C7 can only be <5>
R7C8 can only be <3>
R1C9 can only be <4>
R1C7 can only be <3>
R4C3 can only be <6>
R6C7 can only be <4>
R6C4 can only be <3>
R7C1 can only be <5>
R2C8 can only be <9>
R8C7 can only be <8>
R8C3 can only be <3>
R9C7 can only be <6>
R9C5 can only be <5>
R1C5 can only be <9>
R2C5 can only be <3>
R6C3 can only be <5>
R5C4 can only be <4>
R7C6 can only be <4>
R5C1 can only be <3>
R9C3 can only be <8>
R7C4 can only be <6>
R5C6 can only be <5>
R6C5 can only be <6>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.