One-suit Spider: the game where one good plan decides everything
One-suit Spider is often called the easy version, and in a sense it is: every card is a spade, so every run you build can be moved. But "easy" hides something interesting. Our look-ahead player won about half its games, and whether it landed in the winning half depended heavily on one thing it either achieved early or did not: an empty column before the first deal from the stock.
Across 4,000 deals, the player won 52.8% (95% range 51.2–54.3%). In the 52 games where it cleared a column before touching the stock, it won 51, or 98.1% (89.9–99.7%). That is the clearest picture we have of what thinking ahead buys you in Spider: the same player, the same rules, and a nearly certain win once the board opens up early.
This page sets out those figures, the rules as played on spidersolitaireonline.us, the habits that turn plans into wins, and how we ran the study.
At a glance: what planning changes in one-suit Spider
| Measure | Result | 95% range | Games |
|---|---|---|---|
| Look-ahead player's win rate, all games | 52.8% | 51.2–54.3% | 4,000 |
| Win rate after an empty column before the first deal | 98.1% | 89.9–99.7% | 52 |
| Games where that early empty column happened | 1.3% | 1.0–1.7% | 4,000 |
| Runs completed per game, of 8 | 4.96 | 4.86–5.07 | 4,000 |
| Games with at least 4 runs completed | 56.9% | 55.4–58.5% | 4,000 |
| Moves in a won game, deals included | 117.5 | 117.1–117.9 | 2,111 wins |
What we cannot show you is a greedy-versus-planning pair for Spider. We built only one Spider player, which looks up to 250 positions ahead using the visible cards; we did not run a player that simply takes the nearest move, and we did not build a Spider solver. So the gap we can measure is within one player's games: early open space versus none. It is a big gap.
The early column is rare, though: 1.3% of games. That is why it is worth planning for rather than hoping for. Your opening moves decide whether you get one.
The rules as played on spidersolitaireonline.us
- Cards: two decks, 104 cards, all spades.
- Layout: ten columns. The first four hold six cards, the other six hold five. Only the bottom card of each is face up.
- Stock: the other 50 cards, dealt ten at a time, one onto each column. Five deals, and the stock is not reused.
- Building: any card on a card one rank higher.
- Moving runs: a same-suit run moves as a block. With one suit, every ordered run qualifies.
- Empty columns: take any card or movable run.
- Completing runs: a King-to-Ace run leaves the table by itself. Eight runs and you have won.
The game warns you if you try to deal while a column is empty. Fill it first.
Turning plans into wins
Make the first empty column your first goal
Before you deal even once, look for the shortest column and ask what it would take to clear it. The 98.1% figure above is the reward. A column cleared early lets you reorder runs, rescue buried cards and prepare for the next deal.
Think one deal ahead
Every deal drops a card on every column, including onto runs you have carefully built. Before you click the stock, arrange things so the new cards land where they do the least harm, and fill any empty column with something useful.
Finish runs, do not spread effort
Our player completed at least four of eight runs in 56.9% of games. A finished run disappears and gives space back. Push the run that is nearest to done before starting new ones.
Favor moves that turn a card over
A newly revealed card is new information, and planning runs on information. Our player's scoring rewards uncovering cards and penalizes each card still face down. Copy that habit.
Use Undo as a look-ahead tool
Our player never undoes. You can. Try a line, see what it uncovers, and take it back if it leads nowhere. That alone should put a patient human above our 52.8% floor.
Playing here
One-suit Spider on spidersolitaireonline.us is free in any modern browser on computer, tablet or phone, with no download, no account and no email. You get large cards with zoom, Hint, unlimited Undo, Restart and Auto Play, drag-and-drop or tap controls, a counter for wins, time and moves, sound on or off, fullscreen and a choice of table colors.
How we ran the study
The spidersolitaireonline.us team ran these simulations in September 2026, on the rules this site's Spider actually uses.
- Read the rules from our game's code: 104 cards, ten columns of six and five, a 50-card stock dealt in five rounds with no reuse, any card on one rank higher, only same-suit runs move, anything into an empty column, finished runs removed automatically. We assumed you cannot deal with an empty column; the game shows a warning, but we did not confirm the exact behavior in a browser.
- Wrote the game in Python 3.11, standard library only, in a module called
spider.py. - Tuned, then measured on fresh deals. The player's scoring was set on deals 1 to 30. The results use deals 100,001 to 104,000, which played no part in that tuning.
- Chose a player that sees what you see. At each turn it searches up to 250 positions reachable with the face-up cards, treats unrevealed cards as unknown, and never undoes. It scores positions with points for same-suit links, a smaller reward for any link, a penalty per face-down card, and bonuses for empty columns and newly turned cards. Its win rate is a floor.
- Recorded each game, including whether a column was cleared before the first deal, so we could compare those games with the rest.
- Checked against published work. Blake and Gent (2026) give no one-suit figure, so nothing outside can confirm our 52.8%.
- Added 95% ranges (Wilson score intervals for rates, normal intervals for averages).
- Stated the limits. The early-empty-column result rests on 52 games, so its range is wide. And games where the player cleared a column early may also have been easier deals to begin with; the figure shows how closely the two go together, not proof that the column alone caused every win.
An AI assistant, Claude by Anthropic, helped write and review the simulation code and draft this page. Every figure is the output of running the code, checked by the team before publishing.
Questions
If I clear a column early, will I win?
Very likely. Our player won 51 of 52 such games. It is still not a guarantee, and it happened in only 1.3% of games, so you have to work for it.
Why is there no greedy player figure here?
We only built one Spider player, and it always looks ahead. Rather than guess, we show the gap we did measure.
When should I move up to two suits?
Once you win most one-suit games without leaning on Undo. On two suits, careless builds start to cost much more.
Which other games reward planning in a similar way?
Simple Simon keeps Spider's rules with every card face up, and FreeCell is another open-card planning game. See all games on the games page and more analysis on the blog.
By Admin, spidersolitaireonline.us (Solitairen OOD). Research run September 2026.