# Are there any forms of patience or solitaire that can be solved by logic alone?

Single player games using a single deck of playing cards often called patience or solitaire, generally involve a degree of skill and luck to solve, with card shuffling ultimately being the deciding factor on if the game can be solved/won.

Is there any version of the game with a single player and a standard 52 card poker deck, where every solution can be ultimately positive through deductive reasoning alone?

• FreeCell is 100% deductive after the initial shuffle. Not all games are winnable though. May 21, 2014 at 22:57
• What about 52 Pickup? That game is 100% winnable with deductive reasoning: "If there is still a card on the floor, pick it up." Jun 2, 2015 at 11:17

## 2 Answers

Most patience games, as you've noted, require logical deduction, but most still require a degree of luck.

Spider Solitaire and Mrs. Mopp come close to being solely skill-based, but are both still vulnerable. FreeCell is another game for which almost all games are thought to be playable, though the proportion has not yet been calculated. A rough estimate of winnable games was calculated to be around 99.9987% of games.

However, there are a number of games which do not rely on luck if one assumes the game is winnable (as opposed to games like Aces Up, which are almost solely winnable based on luck). Scorpion is an example of a solitaire game which takes significant skill to actually win, even if the game is winnable. Calculation additionally is almost always winnable, but takes significant amounts of strategy to actually claim a victory (in most cases).

Klondike actually does not fall into this category, as you are blind to the cards much of the time, and frequently would actually be better off taking your chances as opposed to playing logically.

I could go on, and may feel like editing more examples in later, but the short answer is: there are card games for which mostly skill is required, and card games for which, if victory is possible, significant skill is often required to achieve it. Whether there are card games which are provably always solvable remains to be seen.

Solitaire games that are entirely deductive like you mentioned will usually have all their cards exposed at the beginning.

Games like that are called perfect information games – a term usually used in two-player game theory, but in the case of Solitaire applies to games where the position of all the cards is known.

However, it's not always the case that these games are winnable. Famously, deal #11,982 in Microsoft Freecell is the only unsolvable one out of all 32,768 deals available in the original version of the program packaged with Windows 95. What you can determine just from looking at the initial deal is whether the game is winnable or not, purely through deductive logic.

Examples of games like this include:

• Freecell, in any of its implementations.

• Canfield, when all 13 cards in the secondary stockpile are exposed and you're given unlimited redeals. Even so, Canfield is very hard to win, because you're dealing cards from the stockpile three at a time and only allowed to use the top card of three.

• Simple Simon, a game packaged with KPatience in the KDE game suite. It's similar to Spider Solitaire, but it only uses one deck and it deals all 52 cards face-up to the 10 piles with 8, 8, 8, 7, 6, 5, 4, 3, 2, 1 cards in each pile. This game is also very hard to win, but when you do, it's entirely skill-based.