Solitaire Double: two decks, nine columns, and a much friendlier game
Solitaire Double is Klondike played with two full decks: 104 cards, nine tableau columns and eight foundations, two for each suit. It sounds like twice the work, and a game does take longer. But the extra deck makes it far easier to win, not harder.
On this site we like to ask how high the ceiling goes for each game, meaning how many deals can be won with perfect play. For Solitaire Double we have not measured that ceiling yet. What we do have is a strong floor, and it is already high: a simple computer player that never looks ahead and never undoes a move won 81.5% of 10,000 deals. The same kind of player wins only 42.3% of single-deck Klondike.
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Solitaire Double at a glance
| What we measured | Result | Deals | How |
|---|---|---|---|
| Wins by a simple program with no look-ahead | 81.5% (95% range 80.7–82.2%) | 10,000 | Rule-based program, sees only face-up cards (a floor) |
| Same program, single-deck Klondike Turn 1 | 42.3% | 10,000 | For comparison |
| Average length of a win, counting stock clicks | about 268 | 8,145 wins | Same program |
| Passes through the stock in a won game | 2.7 on average | 8,145 wins | Same program |
| Aces that start face down (of 8) | 2.8 on average | 10,000 | Deal inspection |
| Deals with no move at all among the starting face-up cards | 2.7% (single deck: 8.6%) | 10,000 | Deal inspection |
| Ceiling (winnable with perfect play) | Not measured yet | – | No published figure exists either |
Why we can only give a floor here
A floor is what a player achieves without planning ahead or undoing mistakes. A ceiling is what perfect play could achieve. For single-deck Klondike we measured both. For Solitaire Double, with 104 cards and nine columns, we only ran the simple program so far, and we searched the research literature without finding a published figure.
So we will not guess the ceiling. What we can say for certain is that it is at least 81.5%, because the ceiling can never be lower than what a simple program already manages. A careful player using Undo should do better than the program.
Why a second deck makes the game easier
- Two homes for every card. With two foundations per suit, a card that is blocked on one pile can often go on the other.
- More ways to build. For any card, there are four cards of the right rank and opposite color that it can sit on, instead of two.
- Rarely a dead start. Only 2.7% of deals give no move at all among the nine face-up cards, against 8.6% of single-deck deals.
The price is length. A won game took the program about 268 moves, including turning stock cards. Budget a longer session than for a quick game of Klondike.
The rules as this site plays them
Nine columns, 45 cards
Two decks are shuffled together. Nine columns are dealt, holding one to nine cards, with only the top card face up. That uses 45 cards. The other 59 form the stock.
Alternating colors across nine columns
- Build down in alternating colors: a red 8 on a black 9.
- Any face-up run can move as a unit if its bottom card fits.
- A vacant column can be filled only by a King or a King-topped stack.
Turning the 59-card stock
This game turns one card at a time. When the stock runs out, you can turn the waste over and go again, as many times as you like. There is no Turn 3 version of Solitaire Double here; the Draw 3 option takes you to our single-deck Solitaire Turn 3.
Eight foundation piles
There are eight, two for each suit, each built up from Ace to King. You win when all 104 cards are home.
Playing toward the ceiling
Find the buried Aces early
On average 2.8 of the eight Aces start face down. Work on the columns that hide the most cards so those Aces surface sooner.
Use both foundations of a suit
If one 5 of hearts is stuck, the other may be free. Keep an eye on both piles of each suit instead of waiting on one.
Choose the landing spot that frees a column
With two decks, you usually have a choice of where to build. Pick the destination that leaves a column closer to being empty, so a King has somewhere to go.
Treat the stock as a long-term supply
The program's wins used 2.7 passes through the stock on average. There is no limit here, so it is fine to go round several times as the tableau opens up.
Solitaire Double versus one-deck Klondike
If you know Klondike, you already know the rules. What changes is the shape of the game.
- More hidden cards. Nine columns hide 36 cards face down at the start, against 21 in single-deck Klondike. There is more digging to do.
- A bigger stock. 59 cards instead of 24, so each pass through the stock takes longer.
- Far fewer dead ends. With two of every card, there is usually another place for a card to go. That is why the simple program won 81.5% here against 42.3% in one-deck Turn 1.
- Longer games. Our program's wins averaged about 268 moves, counting stock turns.
For many players that makes Solitaire Double the relaxing choice: long, steady games that you win more often than not. If you want a sharper challenge with the same layout ideas, go the other way and try Klondike Turn 3.
How we ran the test
The solitaire-online.us team tested Solitaire Double in September 2026.
- Rules from the page's own game file. This page loads a separate game file built for two decks: 104 cards, nine columns, eight foundations, a 59-card stock and unlimited redeals. It plays Turn 1 only.
- A program version of the game. We extended our single-deck Klondike program to nine columns and two foundations per suit.
- Numbered deals. Each of the 10,000 deals comes from a numbered seed, so the test can be repeated exactly.
- One kind of player. A rule-based program that sees only face-up cards and never undoes a move. That makes the result a floor.
- Running it. All 10,000 deals played to a finish.
- No published check. We found no published winnability figure for two-deck Klondike to compare with, so we say so rather than borrow one.
- The margin of error. A 95% range means the true value falls inside it in 19 of 20 repeats. Here: 80.7–82.2%.
- What the number cannot tell you. It is not the ceiling. A player who looks ahead and uses Undo will beat it, and the true share of winnable deals is higher.
The code behind the floor
The study is written in Python 3.11 with only the standard library. Solitaire Double has its own module, doubleklondike.py, which reuses the Klondike program's move rules. A shared runner deals the games out across processor cores with Python's multiprocessing, and each 95% range is a Wilson score interval.
Claude, the AI assistant built by Anthropic, sped up writing and reviewing the program and gave us a first draft of this page. It did not supply any of the figures. They all come from running the program, and the team checked them before publishing.
By Admin, solitaire-online.us (Solitairen OOD). Study date: September 19, 2026.
Ceiling questions from players
Is Solitaire Double easier than regular Klondike?
By our measure, yes, and by a lot. The same simple program won 81.5% here against 42.3% in single-deck Turn 1.
Why don't you give a winnable percentage?
Because we have not measured it and could not find a published one. We only know it is at least 81.5%.
Can I play Solitaire Double with three cards per turn?
Not on this site. The Draw 3 option opens single-deck Solitaire Turn 3.
Is a two-deck game much longer?
Longer than one-deck Klondike. Won games took the program about 268 moves, counting stock turns.
Where to go after Solitaire Double?
FreeCell Two Decks is another 104-card game, but with every card face up. Or see all 22 games on our games page.