The full reasoning can be found below the Sudoku.
Jun 04 - Very Hard
Puzzle Copyright © Kevin Stone
Share link:
Reasoning
R3C4 can only be <6>
R5C5 can only be <1>
R5C7 can only be <3>
R7C5 can only be <8>
R4C4 can only be <4>
R4C6 can only be <9>
R5C3 can only be <6>
R3C5 can only be <9>
R3C6 can only be <8>
R6C4 can only be <7>
R4C8 can only be <8>
R6C6 can only be <6>
R4C7 can only be <2>
R4C2 can only be <3>
R4C3 can only be <1>
R7C1 is the only square in row 7 that can be <6>
R1C2 is the only square in row 1 that can be <6>
R9C8 is the only square in row 9 that can be <6>
R8C4 is the only square in column 4 that can be <2>
R7C6 is the only square in column 6 that can be <5>
Squares R2C4 and R2C6 in row 2 form a simple naked pair. These 2 squares both contain the 2 possibilities <13>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R2C1 - removing <3> from <345> leaving <45>
R2C8 - removing <1> from <147> leaving <47>
Squares R8C1 and R8C6 in row 8 form a simple naked pair. These 2 squares both contain the 2 possibilities <13>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R8C8 - removing <1> from <179> leaving <79>
R8C9 - removing <3> from <389> leaving <89>
R1C8 is the only square in column 8 that can be <1>
Squares R2C8 and R3C7 in block 3 form a simple naked pair. These 2 squares both contain the 2 possibilities <47>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R2C9 - removing <4> from <458> leaving <58>
R3C9 - removing <4> from <245> leaving <25>
R7C9 is the only square in column 9 that can be <4>
R9C9 is the only square in column 9 that can be <3>
Squares R2C2 and R2C9 in row 2 and R8C2 and R8C9 in row 8 form a Simple X-Wing pattern on possibility <8>. All other instances of this possibility in columns 2 and 9 can be removed.
R1C9 - removing <8> from <289> leaving <29>
R9C2 - removing <8> from <258> leaving <25>
Squares R6C2 and R9C2 in column 2 form a simple naked pair. These 2 squares both contain the 2 possibilities <25>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R2C2 - removing <5> from <578> leaving <78>
Squares R6C2, R6C3, R9C2 and R9C3 form a Type-1 Unique Rectangle on <25>.
R9C3 - removing <25> from <258> leaving <8>
R9C7 can only be <1>
R8C2 can only be <7>
R7C7 can only be <7>
R7C3 can only be <3>
R3C7 can only be <4>
R8C8 can only be <9>
R2C2 can only be <8>
R8C9 can only be <8>
R6C8 can only be <4>
R2C9 can only be <5>
R2C1 can only be <4>
R3C9 can only be <2>
R6C7 can only be <9>
R2C8 can only be <7>
R3C1 can only be <5>
R1C9 can only be <9>
R1C7 can only be <8>
R7C4 can only be <1>
R1C3 can only be <2>
R8C1 can only be <1>
R2C4 can only be <3>
R8C6 can only be <3>
R2C6 can only be <1>
R1C1 can only be <3>
R6C3 can only be <5>
R3C3 can only be <7>
R9C1 can only be <2>
R6C2 can only be <2>
R9C2 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