Spider Solitaire, one suit: the bottom rung of the ladder
Spider with one suit is where this site's difficulty ladder begins. It uses a double deck of 104 cards, every one a spade, spread across ten columns. Your job is to build eight complete runs from King down to Ace; each finished run lifts off the table by itself. With only one suit there is no such thing as a mismatched sequence, and that makes it the most forgiving Spider there is.
How forgiving? Our computer player, which only sees the face-up cards and never takes a move back, won 52.8% of 4,000 one-suit deals. That is the highest win rate any of our players reached among the twelve games on this site. Add a second suit and the same player drops to 5.7%; with four suits it manages 0.2%. Everything else on the site slots in somewhere along that curve.
Since Spider is what this site is named for, this page goes deeper than most: where one suit sits against every other game, how the rules work here, what our 4,000 simulated games say about winning, and exactly how we got the numbers.
The Spider ladder, rung by rung
| Spider version | Player won | Suits completed per game (of 8) | Games with 4+ suits completed | Deals |
|---|---|---|---|---|
| 1 suit (this page) | 52.8% (51.2–54.3%) | 4.96 | 56.9% | 4,000 |
| 2 suits | 5.7% (5.0–6.5%) | 0.83 | 6.3% | 4,000 |
| 4 suits | 0.2% (0.08–0.5%) | 0.05 | 0.2% | 2,000 |
Look at the middle column. With one suit, the average game ends with almost five of the eight runs finished, even counting the games it lost. With two suits, it averages less than one. Our player is the same program in all three rows; only the number of suits changes. That makes this the cleanest comparison in the whole study.
And the rest of the site
Against the other games, one-suit Spider sits at the top of our player results, just ahead of Diplomat (47.9%) and classic Klondike Turn 1 (42.3%). Different games have different computer players, so treat those comparisons as a rough guide. For an outside reference, the solitairex.io homepage groups Spider with one suit among its "quick wins" at 70–84% for its players, with no method given. A human with Undo should comfortably beat our program, which never takes a move back.
How Spider works on this site
The setup
- 104 cards (two decks) in one suit.
- Ten columns: the first four get six cards, the other six get five. Only the last card in each column is face up.
- The stock: the remaining 50 cards, dealt out ten at a time, one onto every column. That gives you five deals in total, and the stock is not reused.
How cards move in Spider
- Any card can go on a card one rank higher, whatever its suit.
- A run can only move as a block if every card in it is the same suit. With one suit, that is always true.
- Any card, or any movable run, can go into an empty column.
- When you complete a run from King down to Ace in one suit, it is removed from the table automatically.
The game warns you if you try to deal while a column is empty, so fill your spaces before you click the stock. You win when all eight runs are complete.
What 4,000 games taught us about winning
An early empty column is almost a guaranteed win
In 52 of our 4,000 games, the player managed to clear a whole column before it dealt from the stock for the first time. It went on to win 51 of those 52. That is a small group, so the honest range is wide, roughly 90% to 99.7%, but the message is clear: an empty column is the most valuable thing in Spider. The catch is that it happened in only 1.3% of games. So you rarely get one for free, and it is worth working hard for.
Finishing runs is what wins
In 56.9% of games our player completed at least four of the eight runs. Completed runs leave the table and free up space, which makes the next run easier. Build toward the run that is closest to done rather than spreading effort evenly.
Expect a game of around 120 moves
Games the player won took 117.5 moves on average, counting each deal from the stock as one move. If you are well past that and still stuck, a Restart and a new plan is often faster than grinding on.
Keep face-down cards shrinking
Our player scores positions partly by how many cards are still face down, and it treats a freshly turned card as a bonus. It is a sound rule for humans too: a move that uncovers a card usually beats a move that merely tidies.
Fill every gap before you deal
Our player always fills empty columns before dealing, because a deal drops a card on every column, including the empty ones. Use a space for something useful before you give it away.
Features on spidersolitaire.us
Spider on spidersolitaire.us is free and runs in any modern browser on computer, tablet or phone. Nothing to download, no account, no sign-up and no email address. The cards are large and clear, and a zoom control makes the board bigger. You get Hint, unlimited Undo, Restart, Auto Play to finish a won game, and drag-and-drop or tap controls. Wins, time and moves are tracked for the current game, sound can be turned off, and you can go fullscreen and choose a table color.
Behind the numbers: how we ran the study
The spidersolitaire.us team ran this study in September 2026. The question was simple: how much harder does each extra suit make Spider, on the rules our own game uses? Here is every step.
- Started from the code that runs our game. 104 cards, ten columns of six and five, 50 cards in the stock dealt one per column with no reuse, any card on one rank higher, only same-suit runs move, any card in an empty column, and finished runs removed automatically. One rule we had to assume: that you cannot deal while a column is empty. The game shows a warning there, but we did not confirm the exact behavior in a browser.
- Rebuilt Spider as a program. Our one-suit games used spades only, just like the site.
- Dealt numbered hands. Every shuffle comes from a numbered seed. We first tried the player on deals 1 to 30 to set its scoring, then measured it on deals 100,001 to 104,000, which had played no part in that tuning.
- Chose the player. A program that looks a short way ahead using only the face-up cards, treats any newly uncovered card as unknown, and never undoes. That makes its result a floor for a careful human. We did not build a solver that sees every card for Spider.
- Played every deal to the end. 4,000 one-suit games, the same number as for two suits.
- Looked for published figures. The main study we checked, Blake and Gent (Journal of Artificial Intelligence Research, 2026), reports Spider with four suits at 98.5% winnable when every card is known. It does not report a one-suit figure, so our one-suit number has nothing direct to be checked against.
- Worked out the margin of error. The 95% range for 52.8% is 51.2% to 54.3%: the true rate for this player almost certainly falls in there.
- Named the limits. Our player never undoes and only looks a short way ahead, so people who plan and use Undo will win more. The "empty column early" result comes from just 52 games, so its range is wide.
The code behind the ladder
All of it is Python 3.11, standard library only. Spider has its own module, spider.py. At every turn the player runs a best-first search over up to 250 positions it can reach with the cards it can see, and picks the line with the best score: points for each same-suit link, a smaller reward for any link, a penalty for each face-down card, and a bonus for empty columns and newly uncovered cards. A shared runner spread the 4,000 games over 19 processes on a 20-core Windows machine; the one-suit run took about 21 minutes.
Percentages carry Wilson score 95% intervals. We used Claude, an AI assistant from Anthropic, to help write and review the simulation code and to draft this page. None of the numbers came from the AI: each one is the output of running the code, reviewed by the team against the published research before it went live.
Ladder questions, answered with data
Is one-suit Spider too easy?
It is the gentlest game on the site by our numbers, but our player still lost almost half its games. There is plenty to learn before moving up.
When should I move to two suits?
When you win most one-suit games without leaning on Undo. The jump is steep: our player went from 52.8% to 5.7%. The two-suit page explains why.
Why does the game stop me dealing?
It warns you when a column is empty. Fill the space first; then deal.
Is every one-suit deal winnable?
We did not test that with a solver, so we cannot say. Published research puts even four-suit Spider at 98.5% winnable with perfect knowledge, which suggests very few one-suit deals are truly lost.
What other game plays like Spider?
Try Yukon, where you can also move cards that are not in order, or FreeCell for a game with everything face up. The full list is on the games page, and more Spider analysis is on the blog.
By Admin, spidersolitaire.us. Research run September 2026.