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

Average	656
Std. Deviate	103
Minimum	431
Maximum	2059

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

	Easiest		Hardest
No	Mean 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: