Freecells

If you don't know what Freecell, the solitaire card game is, here's more than you will ever need to know at Wikipedia.

A week or so ago I got into a discussion with the Hubby who claimed that he had heard from various sources that ALL freecell games are solvable. Here's another thing you need to learn about men:- they will believe in all external sources except their wives! (Okay, to be fair to him, only on certain subjects and occasionally.) I had my doubts but was too lazy to look it up online until today. Evidently, a few are universally (and I use that term loosely) agreed to be unsolvable. For the fun of it, I'll post them on my random blog. :)

According to one Robert McMillan, there are 8 unsolvable games in the Window FreeCell game, and they are:

Games Nos.

11,982
146,692
186,216
455,889
495,505
512,118
517,776
781,948

Also from Wikipedia:

Game 11982

When Microsoft FreeCell became very popular during the 1990s it was not clear which of the 32,000 deals in the program were solvable. To clarify the situation, Dave Ring started The Internet FreeCell Project and took on the challenge of trying to solve all the deals using human solvers. Ring assigned 100 consecutive games chunks across volunteering human solvers and collected the games that they reported to be unsolvable, and assigned them to other people. This project used the power of crowdsourcing to quickly converge on the answer. The project was finished in October 1995, and only one game defied every human player's attempt: #11,982. Although this deal has defied every attempt to solve it, even by several exhaustive-search software solvers, no definitive proof has yet been offered that it is, in fact, unsolvable.

Several more presumably unsolvable instances were also discovered when Windows XP updated Freecell to 1,000,000 game instances, but 11,982 is still the most infamous of them.

11,982 is inherently difficult due to the large number of aces and other small cards high in the stack, as well as the high cards being relatively evenly distributed among the stacks, requiring one to use many of the cells to get to any useful cards.

Game 11,982 in Kpatience is identical to the one on Windows.

Awwwww man, how did I miss being one of the human solvers for this project? LOL