     Sudoku Solution Path   Copyright © Kevin Stone R8C2 can only be <8> R1C9 is the only square in row 1 that can be <6> R2C2 is the only square in row 2 that can be <4> R2C8 is the only square in row 2 that can be <8> R7C9 is the only square in row 7 that can be <5> R5C2 is the only square in column 2 that can be <5> Intersection of row 5 with block 5. The values <26> only appears in one or more of squares R5C4, R5C5 and R5C6 of row 5. These squares are the ones that intersect with block 5. Thus, the other (non-intersecting) squares of block 5 cannot contain these values.    R4C4 - removing <6> from <568> leaving <58>    R4C5 - removing <6> from <34567> leaving <3457>    R6C4 - removing <26> from <2689> leaving <89>    R6C5 - removing <26> from <24679> leaving <479>    R6C6 - removing <2> from <12489> leaving <1489> R5C4 is the only square in column 4 that can be <6> Intersection of row 7 with block 7. The values <13> only appears in one or more of squares R7C1, R7C2 and R7C3 of row 7. These squares are the ones that intersect with block 7. Thus, the other (non-intersecting) squares of block 7 cannot contain these values.    R8C1 - removing <3> from <369> leaving <69>    R9C1 - removing <1> from <1269> leaving <269>    R9C2 - removing <1> from <12> leaving <2> R1C2 can only be <1> R2C9 is the only square in row 2 that can be <1> R9C8 is the only square in row 9 that can be <1> R3C9 is the only square in column 9 that can be <2> R3C3 can only be <3> R7C3 can only be <1> R4C3 can only be <6> R6C3 can only be <2> R6C7 is the only square in row 6 that can be <6> R7C1 is the only square in row 7 that can be <3> R7C4 is the only square in column 4 that can be <2> R5C6 is the only square in column 6 that can be <2> Squares R8C1 and R8C5 in row 8 form a simple locked pair. These 2 squares both contain the 2 possibilities <69>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.    R8C8 - removing <9> from <379> leaving <37>    R8C9 - removing <9> from <379> leaving <37> Squares R1C5 and R1C8 in row 1 and R5C5 and R5C8 in row 5 form a Simple X-Wing pattern on possibility <9>. All other instances of this possibility in columns 5 and 8 can be removed.    R6C5 - removing <9> from <479> leaving <47>    R8C5 - removing <9> from <69> leaving <6>    R9C5 - removing <9> from <469> leaving <46> R8C1 can only be <9> R9C5 can only be <4> R9C9 can only be <9> R6C5 can only be <7> R7C6 can only be <9> R9C1 can only be <6> R7C7 can only be <4> R6C9 can only be <4> R4C7 can only be <7> R3C6 can only be <8> R6C6 can only be <1> R4C9 can only be <3> R3C7 can only be <9> R4C5 can only be <5> R8C9 can only be <7> R5C8 can only be <9> R5C5 can only be <3> R1C8 can only be <7> R6C1 can only be <8> R4C6 can only be <4> R8C8 can only be <3> R1C1 can only be <2> R3C4 can only be <5> R4C4 can only be <8> R2C5 can only be <2> R6C4 can only be <9> R4C1 can only be <1> R1C5 can only be <9> R2C1 can only be <5> R3C1 can only be <7> [Puzzle Code = Sudoku-20191023-VeryHard-024725]    