Solitaire Double: the two-deck rung that is kinder than it looks

Picture Klondike, then double everything. Solitaire Double shuffles two full decks into one 104-card pack, lays out nine tableau columns in place of seven, and asks you to fill eight foundations rather than four. It looks like a much bigger job. On our test bench it turned out to be one of the gentlest games on spidersolitaire.us.

The same simple computer player that wins 42.3% of ordinary Klondike deals won 81.5% of 10,000 Solitaire Double deals. On our difficulty ladder, where every game is measured against Spider, that is the highest win rate any of our no-peeking computer players recorded, above even one-suit Spider. The reason is simple and worth understanding before you play: with two of every card, there is almost always somewhere for a card to go.

Solitaire Double on the ladder

These are floors: each comes from a program that only sees what you see and never takes a move back. The Spider and Klondike players are built differently, so read the table as a rough ranking of how kind each game is to straightforward play, not as exact odds for a person. A careful player with Undo will do better in all of them.

The two-deck layout, piece by piece

• Cards: two standard decks, 104 cards in all.
• Tableau: nine columns holding one to nine cards, 45 cards in total, with only the bottom card of each column face up.
• Stock: the remaining 59 cards, turned one at a time. Solitaire Double on this site is played at Turn 1; the Draw 3 option sends you to single-deck Solitaire Turn 3 instead.
• Redeals: unlimited. When the stock runs out, the waste turns back over.
• Foundations: eight piles, a pair per suit, every one climbing from Ace to King.
• Building: down in alternating colors, as in Klondike. Ordered runs move together.
• Empty columns: Kings only, or a run headed by a King.

Why two decks make the game easier

Twice the landing spots

In ordinary Klondike a red 7 has exactly two possible homes in the tableau: the two black 8s. In Solitaire Double it has four. Every card has twice as many places to go, and two foundations per suit give it twice as many ways home. That is the most likely reason our player's win rate almost doubled.

Fewer dead starts

We checked every opening layout. In single-deck Klondike, 8.6% of deals have no move at all among the face-up tableau cards. With nine face-up cards drawn from two decks, that falls to 2.7%. You will very rarely have to go straight to the stock.

Aces are buried, but there are eight of them

On average 2.8 of the 8 Aces start face down in the tableau. That sounds like a lot, but with two Aces of every suit you rarely need a particular one to start a foundation.

Playing it well

• Pick your target twin. With two 8s of each color on the table, choose the one that will free the more useful column, usually the one sitting on more face-down cards.
• Work the long columns early. The ninth column holds nine cards, eight of them hidden. Moves that start digging there pay off for the rest of the game.
• Build both foundations of a suit evenly. Racing one heart pile far ahead while the other stalls sends up cards you may still want in the tableau to catch lower cards of the other color.
• Save Kings for empty columns. The Kings-only rule applies here too, and with eight Kings in the deck you will usually have one ready when a column clears.
• Expect a long game. Our player's wins took about 268 moves on average, draws included, against 126 for single-deck Klondike, and went through the stock about 2.7 times. Settle in.

Mistakes that cost two-deck games

• Treating it like ordinary Klondike. Single-deck habits, such as waiting for the one card that fits, waste time here. Look for the second copy of the card you need before you dig for the first.
• Filling an empty column with the first King you see. There are eight Kings. Choose the one whose column move uncovers the most face-down cards.
• Ignoring the right-hand columns. The last three columns hide 21 of the 36 face-down cards between them. Leave them untouched for too long and you run out of moves while most of the deck is still hidden.
• Cycling the stock without a plan. Redeals are unlimited, so there is no penalty for going through again, but every pass without a tableau move is a sign you should rethink rather than click faster.
• Giving up on a slow start. Our player won more than four deals in five. A game that looks stuck after the first pass usually is not.

Built for a nine-column table

Nine columns and 104 cards make screen space precious, so the zoom control and fullscreen mode earn their keep here. Beyond that you get the whole spidersolitaire.us kit at no cost and with no sign-up: Hint when you are stuck, Undo as often as you like, Restart for the same deal, Auto Play to wrap up, drag or two-tap moves, and a live count of wins, time and moves. It runs in the browser on desktop, tablet or phone; sound and felt color can be changed in settings.

How we put Solitaire Double on the ladder, step by step

The spidersolitaire.us team tested Solitaire Double on September 19, 2026, as part of the study behind our difficulty ladder.

1. Started from the page's own script. Solitaire Double has a dedicated two-deck version of the Klondike engine: 104 cards, nine columns of one to nine, a 59-card stock, unlimited redeals, alternating-color builds, runs that move together and Kings-only spaces. It is Turn 1 only; the Draw 3 switch leads to the single-deck game.
2. Rebuilt it as a program by extending our single-deck Klondike player to nine columns and two foundations per suit.
3. Dealt 10,000 numbered hands, seeds 1 to 10,000, so anyone with the code gets exactly the same deals.
4. Used a floor player: it sees only face-up cards, follows a priority list of moves and never undoes.
5. Played every deal to the end, recording wins, moves and stock passes, and inspected every opening layout.
6. Looked for published figures. The main study we checked against, Blake and Gent (2026), does not cover two-deck Klondike, so there is nothing direct to compare with.
7. Worked out the margin of error. The 95% range for 81.5% is 80.7% to 82.2%.
8. Named the limits. 81.5% is what a no-peeking program achieved, so it marks a minimum; we did not run an all-seeing solver on Solitaire Double, so we cannot say how many deals are winnable in principle.

Two decks in code

doubleklondike.py is a small Python 3.11 module, standard library only, that borrows the move rules of our single-deck klondike.py and widens them to nine columns and paired foundations. Spread across 19 processes, all 10,000 deals were played in roughly five seconds. The 95% ranges are Wilson score intervals. Anthropic's AI assistant, Claude, helped us build and check this module and draft the page. The results are the program's output; the AI did not supply any of them.

Questions about Solitaire Double

Is Solitaire Double harder than normal Klondike?

Easier, by a wide margin: our no-peeking program won 81.5% of two-deck deals and 42.3% of single-deck ones.

Can I play it with three-card draws?

Not in the two-deck version here. Choosing Draw 3 takes you to single-deck Solitaire Turn 3.

What are the eight home piles for?

Each suit appears twice in a 104-card pack, so each suit is given a pair of piles to climb.

How many moves does a two-deck win need?

Longer than single-deck Klondike. Our player needed around 268 moves to win, roughly twice as many.

What should I try after this?

If you want another two-deck game, try FreeCell Two Decks; if you want a real climb, try two-suit Spider. The classic single-deck game is explained in our Klondike guide.

By Admin, spidersolitaire.us (Solitairen OOD). Research run September 2026.