http://freecellproject.com/play/?game=917

Freecell 917 is one of the most difficult games.

You might be a genius, if you can solve this within 10 minutes.

The following games are the most difficult games

169, 178, 258, 454, 617, 718, 1689, 1941, 2021, 2350, 2577, 2607,
2670, 2772,
3285, 3342, 3349, 3685, 3772, 3788, 3801, 3973, 4257, 4368, 4540,
4591, 4714,
4946, 5179, 5374, 5453, 5482, 5490, 5548, 5557, 6343, 6673, 6745,
6751, 6768,
7107, 7160, 7600, 7700, 8005, 8323, 8534, 8591, 8652, 8678, 8749,
8820, 9250,
9385, 9538, 9617, 9700, 10589, 11281, 11386, 11409, 11430, 11677,
11854,
12211, 12313, 13015, 14051, 14188, 14676, 14795, 14879, 14965, 14977,
15023,
15099, 15130, 15133, 15164, 15227, 15238, 15710, 15746, 15905, 15939,
16191,
16575, 16576, 17277, 17524, 17764, 17768, 18623, 18992, 19410, 19484,
19633,
19763, 19861, 20055, 20251, 20589, 20715, 20912, 21051, 21185, 21278,
21785,
21896, 21899, 22332, 24063, 24457, 24549, 24735, 25123, 25155, 25450,
25599,
25602, 25790, 25856, 25995, 26093, 26183, 26197, 26369, 26421, 26576,
26693,
26694, 26710, 27188, 29001, 29154, 29198, 29345, 29704, 30000, 30108,
30394,
30615, 30712, 30801, 31044, 31266, 31465, 31601, 31647, 31729, 31918,
31945.