FreeCell Solver: Is Every Deal Solvable?
FreeCell is the solitaire game people call winnable almost every time, because all 52 cards are face up. Almost is the interesting word. This page reports what our own solver found on 12,000 numbered deals, says clearly what it did not prove, and explains how the Solver tool in the game uses the same engine.
What our solver found
We ran the solver over 12,000 numbered FreeCell deals. It found a complete winning line for 11,304 of them, which is 94.2%, and each line was replayed move by move to confirm it wins.
| Deals tested | Proved winnable | Share |
|---|---|---|
| 12,000 | 11,304 | 94.2% |
What about the other 5.8%?
For the remaining 696 deals the solver did not find a winning line. That is not the same as proving them unwinnable: a search that stops at its budget cannot tell the difference between a deal with no solution and a deal whose solution is hard to find. We therefore do not claim that 5.8% of FreeCell deals are impossible, only that this is the share we could not prove. Solitaire Play never deals these games; every new deal and Daily Challenge comes from the proved set.
Why FreeCell is so winnable
Everything is visible, so the whole game is planning, not luck. You have eight columns, four free cells and four foundations, and a correctly ordered run can move together: the longest run is (free cells + 1) × 2 to the power of the number of empty columns. An empty column is worth far more than a free cell, which is why strategy guides tell you to empty one on purpose.
More on technique in the FreeCell strategy guide.
The Solver tool in the game
Open the menu in a FreeCell game and choose Solver to ask whether the current position can still be won, to watch a demonstration of a winning line, or to go back to a position that is still winnable. A game finished with the demonstration does not count toward your stats. Like the library figures, the answer comes from a search with a limit, so it is a proof when it says yes and not a verdict when it gives up.
Frequently asked questions
Is every FreeCell deal solvable?
Not guaranteed. In our run of 12,000 deals the solver proved 94.2% winnable; for the other 5.8% it found no winning line, which does not prove they are unwinnable. Solitaire Play deals only from the proved set.
How many FreeCell deals did the solver test?
12,000 numbered deals, of which 11,304 were proved winnable and replayed.
Can I use the solver while I play?
Yes. The Solver in the menu can tell you whether your current position can still be won, show a winning line, or take you back to a position that still has one. Demonstrated wins do not count toward your stats.
Why does the solver sometimes not give an answer?
It searches within a limit. A deal that it could not finish within that limit is reported as unproven, not as impossible.