Microsoft FreeCell

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FreeCell
A component of Microsoft Windows
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FreeCell 7.png
FreeCell on Windows 7
Details
Type Computer game
Included with Windows 95 up to Windows 7, Windows 10
Related components
Hearts, Solitaire, Spider Solitaire

FreeCell, also known as Microsoft FreeCell,[1] is a computer game included in Microsoft Windows,[2] based on a card game with the same name.

History

The first computer version of the game is believed to have been created by Paul Alfille in 1978 for the PLATO system.[3] Microsoft developer Jim Horne, who learned the game from the PLATO system, implemented a version with color graphics for Windows. It was first included in Microsoft Entertainment Pack Volume 2 and later the Best Of Microsoft Entertainment Pack.[4] It was subsequently included with Win32s as an application that enabled the testing of the 32-bit thunking layer to ensure that it was installed properly.[5][3] However, FreeCell remained relatively obscure until it was released as part of Windows 95.[6] In Windows XP, FreeCell was extended to support a total of 1 million card deals.[3]

Variations

Today, there are FreeCell implementations for nearly every modern operating system as it is one of the few games pre-installed with every copy of Windows. Prior to Windows Vista, the versions for Windows were limited in their player assistance features, such as retraction of moves. The Windows Vista FreeCell implementation contains basic hints and unlimited move retraction (via the Undo menu choice or command),[7] and the option to restart the game. Some features have been removed, such as the flashing screen to warn the player of one move remaining.

FreeCell is not included in the Windows 8 operating system. However, the Microsoft Solitaire Collection can be downloaded for free from the Windows Store, which includes FreeCell plus four other solitaire games. Unlike the original FreeCell, this version allows unlimited move retraction. The newer version of FreeCell is included in the Windows 10 operating system, along with the other four games from the Microsoft Solitaire Collection.

Easter eggs

In the earliest versions, games numbered -1 and -2 were included as a kind of Easter egg to demonstrate that there were some possible card combinations that clearly could not be won; these games had the cards organized in such a way as to make clearing any of them virtually impossible. The Windows Vista and Windows 7 versions also included games numbered -3 and -4 which organized the cards for a guaranteed win, which can complete itself in its entirety by either dragging an ace to the home pile or by right clicking.

In versions prior to Windows Vista, if the user pushes the combination of Ctrl+Shift+F10 at any time during the game, the user will be presented with a tool used by the developers during testing.[8]

Solving

The original Microsoft FreeCell package includes 32,000 games, generated by a 15-bit, pseudorandom-number seed.[9] These games are known as the "Microsoft 32,000". Later versions of Microsoft FreeCell include more games, some over one million, of which the original 32,000 are always a subset. All hands in the Microsoft 32,000 have been beaten except for game #11982.[6]

A statement in the original Help file remains through modern Microsoft versions: "It is believed (although not proven) that every game is winnable." However, this statement does not hold true for hands numbered "-1" and "-2" that were included as "Easter eggs" and were already known at the time to be unsolvable.

The Internet FreeCell Project

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 ran from August 1994 to April 1995, and only one game defied every human player's attempt: #11,982.[10]

Unsolvable combinations

Out of the current Microsoft Windows games, there are eight that are unsolvable: the games numbered 11,982; 146,692; 186,216; 455,889; 495,505; 512,118; 517,776 and 781,948.[11] Exhaustive search has shown that five free cells (rather than the standard four) are required for these games. Adrian Ettlinger, using Don Woods' solver, has used the same random hand generator as Microsoft Windows FreeCell to explore a further 10 million games. Of the 130 unsolvable games in the first 10 million, all of them require 5 free cells. Ryan L. Miller with the help of others explored 100 million games, with a total of 1282 being unsolvable. This gives FreeCell a winnable rate of about 99.998718%.[3]

References

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External links