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Statistics on Difficulty of Sudokus

There is now reliable, objective way to measure the difficulty of a given Sudoku. Therefore these statistics compiled from how fast or slow humans solved the Sudokus on the one hand, and how many people solved a given Sudoku on the other hand.

Average Solving Time

All times are given in Seconds.

Overall Statistics

Average656
Std. Deviate103
Minimum431
Maximum2059

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

EasiestHardest
NoMean Time [s]Sudoku Mean Time [s]Sudoku
1 432 2009-11-15 2060 2006-10-14
2 432 2010-08-04 1336 2010-04-21
3 436 2009-08-04 1334 2009-11-18
4 439 2007-04-03 1034 2009-12-07
5 440 2007-01-18 1023 2007-09-07
6 443 2006-10-04 970 2007-08-12
7 450 2009-12-09 968 2008-10-29
8 451 2006-11-25 949 2008-02-14
9 451 2009-11-17 933 2010-07-03
10 451 2009-12-03 930 2007-03-04
11 451 2006-12-20 925 2007-07-25
12 452 2007-06-16 921 2007-12-22
13 456 2007-01-05 921 2010-06-27
14 459 2006-11-06 914 2007-09-27
15 461 2006-12-23 906 2009-03-09

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often:

NumberSudoku
352009-08-01
392009-06-26
392009-09-05
412009-07-28
412009-08-03
412009-04-03
412008-12-24
412009-06-18
422009-06-20
422010-09-06
422009-07-03
422007-12-22
422009-08-05
432009-06-05
432007-07-25