Simple Simon Solitaire: an open staircase of cards, and what it reveals
Simple Simon is Spider without the secrets. One pack is dealt face up into ten columns shaped like a staircase, from eight cards down to one. There is no stock and nothing hidden, so every decision is made with the whole deal in view. The aim is to build each suit from King down to Ace in a column; a finished suit is cleared away.
Our solver, which sees exactly what you see, found a win in 86.5% of 3,000 deals on this site's rules, proved 5.2% impossible, and left 8.3% unfinished. So between 86.5% and 94.8% of deals can be won. One honest caution: our result differs from the published research, and we explain that below.
What a Simple Simon deal tells you
| What we measured | Result | Deals | How |
|---|---|---|---|
| Same-suit links already in place in the deal | 0.76 on average (95% range 0.73–0.79) | 3,000 | Deal inspection |
| Deals with no legal first move | They exist, for example our deal number 81 | — | Deal inspection |
| Solved | 86.5% (85.3–87.7%) | 3,000 | Best-first solver, 200,000-position limit |
| Proven impossible | 5.2% (4.4–6.0%) | 3,000 | Same solver |
| Unfinished at the search limit | 8.3% | 3,000 | Same solver |
| Published figure (Blake & Gent, 2026) | 97.450% winnable | — | Does not match ours; see below |
Simple Simon rules on klondike.nz
The layout
- One pack of 52 cards, all face up.
- Ten columns: three of eight cards, then seven, six, five, four, three, two and one.
- No stock and no free cells.
Moves
- A card may go on the next higher card of any suit: any 5 on any 6.
- A run of cards in the same suit and in order can be moved together, however long it is. A mixed-suit run can't.
- Any card may go into an empty column.
- When a column holds a complete suit from King to Ace, it is cleared. You win when all four suits are cleared.
Reading the deal
Count the ready-made links
A "link" is a card sitting directly on the next higher card of its own suit, such as the 8 of hearts on the 9 of hearts. The average deal starts with 0.76 of them, so most deals give you one or none. Each one is a small head start, because same-suit runs are the ones you can move as a block.
Check that you can move at all
Every card is face up and anything can go on anything one rank higher, so a stuck start seems impossible. It isn't: some deals have no legal first move whatsoever. Our deal number 81 is one: none of its ten exposed cards can go anywhere. It is rare, but if you meet one, it isn't you.
Find the short columns
The staircase gives you columns of one, two and three cards. Those are the quickest to empty, and an empty column takes any card, which makes it the most powerful tool in the game.
Strategy
Build in suit when you can
Any-suit building is allowed, but only same-suit runs can move as a unit. Putting the 5 of clubs on the 6 of clubs keeps the pair mobile; putting it on the 6 of hearts creates a joint that can only be taken apart one card at a time.
Use the short columns early
Empty one of the small columns early and use it to sort mixed runs into suit order.
Aim for complete suits
A completed King-to-Ace suit leaves the table, taking thirteen cards with it and often freeing a column. Once a suit is nearly assembled, finishing it is usually the best use of your moves.
Plan, test, take back
With every card visible, Simple Simon is a planning game. If a plan jams, go back and try the other order.
A worked start
A typical opening goes like this. The single card in the last column can usually go onto a card one rank higher somewhere, which empties that column at once. Use the empty column to sort the most tangled short column into same-suit order, then look for a suit whose King is near the bottom of a column: that is where a full suit will be assembled and cleared. Clearing that first suit early gives you room for everything else.
Our result and the published one
The 2026 study by Charlie Blake and Ian Gent at the University of St Andrews (Journal of Artificial Intelligence Research) reports that 97.450% of Simple Simon deals can be won, implying no more than about 2.55% are impossible. Our solver proved 5.2% of deals impossible, with a 95% range of 4.4–6.0%. That is more than the published figure allows.
We checked our side: a completely separate brute-force search confirmed six of our "impossible" deals, and deal 81 has no legal move at all. As far as we can tell, the rules we took from this site's code match the rules in the paper. We have not found the cause of the difference, so treat our Simple Simon figures with caution until it is resolved.
Similar games
If you like Simple Simon, you will probably enjoy Spider Solitaire (hidden cards and a stock) and Scorpion (in-suit building and bigger moves). For a different open-card puzzle, try Flower Garden.
Playing Simple Simon on klondike.nz
Free, with nothing to download or sign up for, in any modern browser on a computer, tablet or phone. Large, clear cards and a zoom control make the staircase easy to read. Drag or tap to move, and use Hint, unlimited Undo, Restart and Auto Play. The game tracks wins, time and moves.
Where these numbers come from
The klondike.nz team measured Simple Simon in September 2026 with this site's own rules.
- Rules from our code. The game's Simple Simon settings: ten face-up columns of 8, 8, 8, 7, 6, 5, 4, 3, 2 and 1; any-suit building; same-suit runs move with no length limit; any card into an empty column; completed suits removed.
- A program copy of the game. We built Simple Simon in a program shared with Scorpion.
- Numbered deals. 3,000 deals from numbered seeds, so the test can be repeated exactly.
- Reading each deal. We counted same-suit links and checked for a legal first move.
- The solver. It sees all 52 cards, as you do, and tries up to 200,000 positions per deal.
- A separate check. An independent brute-force search re-examined six deals the solver called impossible and agreed with all six.
- Comparison. Our impossible share is higher than the published study implies, for reasons we haven't found yet (see above).
- Limits. With 8.3% of deals unfinished, the winnable share is somewhere from 86.5% to 94.8%, and until the difference with the published figure is explained, these numbers should be read with care.
Under the bonnet
The code is Python 3.11 with only the standard library, in spiderlike.py, which also runs Scorpion. The solver is a best-first search that expands the most promising position next and keeps a record of positions already seen, with a limit of 200,000 positions per deal. The brute-force check is in verify_simplesimon_bruteforce.py. Deals run in parallel across processor cores with multiprocessing, and ranges are Wilson score 95% intervals. We used an AI assistant, Claude by Anthropic, to help write and review the code and draft this page; the figures come only from running the code.
Questions players ask
Is Simple Simon really simple?
The rules are, and nothing is hidden. The play takes real planning, because only same-suit runs move as a block.
Can a Simple Simon deal be impossible?
Yes. Some deals have no legal first move at all, and our solver proved 5.2% impossible, although that figure is higher than the published one.
Can I move a run of mixed suits?
No, only runs in a single suit move together. A mixed run has to be taken apart card by card.
Are any cards held back?
No. All 52 cards are dealt face up at the start.
Who ran this study?
The klondike.nz team; read more on our about page.
By Admin, klondike.nz. Study date: 19 September 2026.