Difficult Sudoku Strategy Is There A Sudoku So Difficult That It Can Only Be Solved By Exhaustive Enumeration?

Is there a Sudoku so difficult that it can only be solved by exhaustive enumeration? - difficult sudoku strategy

I wanted to do things in games, but Sudoku is a logic game. There are many strategies for solving Sudodu, and can do all this in newspapers and magazines. But the network is much more difficult. There are so tough that no solution is found), with the exception of the use of brute force number crunching (by computer to a solution?