The story behind the game Freecell that comes with Windows is interesting. The help file includes the following mysterious line: “It is believed (although not proven) that every game is winnable.” The game lets you choose the number of the game you would like to play, from 1 to 32,000. So it wasn’t long before an early internet project started where people divided up all of the games into 320 batches of 100 games and tried to solve them all. And not long after that they came up with only one game that couldn’t be won, game number 11,982. I’ve always suspected that the programmer did that on purpose and 11-9-82 was an important date for him (probably not his birthday since it was written in 1995). I found this out a few years ago.
What I didn’t realize was that when Microsoft introduced Windows XP, they increased the number of games you can play up to 1 million, good news for the people who had played all 32,000. At this point the game was popular enough that people had written computer programs that would try to solve different games, so rather than doing parallel human processing, computers chewed through the games and found 8 more that are unsolvable.