LONDON: A Finnish mathematician has claimed to have devised the world’s hardest Sudoku, which is specifically designed to be unsolvable to all but the sharpest minds.
According to Arto Inkala, who devised the game, on the difficulty scale by which most sudoku grids are graded — with one star signifying the simplist and five stars the hardest — this puzzle would score an eleven.
Sudoku is a familiar challenge to newspaper readers and puzzle enthusiasts, requiring each vertical line, horizontal line and nine-square box to contain every number from one to nine.
The particular difficulty in this version lies in the number of deductions the player has to make in order to fill in a single number on the grid.
Instead of being able to spot where a number goes based solely on the boxes that have already been filled in, most moves will face you with two or more spaces where a number could fit. Only one of these is correct, but to find it the player must examine all possible options for their next move and perhaps the move after that, continuing in the same vein until all but one potential route results in a dead end.
Inkala said that the most difficult parts of the grid require you to think 10 moves ahead, exploring a series of permutations at each stage in order to eliminate all routes other than the right one. “It is difficult to say if any one (puzzle) is the hardest or not, because I believe the hardest one is not yet discovered,” the Telegraph quoted him as saying.