Spider Solitaire, two suits: the steepest step on the ladder
Two-suit Spider uses the same 104 cards, ten columns and five deals as the one-suit game, but half the cards are now hearts. That sounds like a small change. On our difficulty ladder it is the biggest single jump anywhere on the site.
Our computer player, the same program that won 52.8% of one-suit games, won just 5.7% of 4,000 two-suit deals. It averaged less than one completed run per game, down from almost five. No other rule change we measured, not even going from Turn 1 to Turn 3 in Klondike, hit a player this hard.
This page explains why the second suit bites so deep, shows where two-suit Spider sits among the other games, and sets out how we measured it.
One extra suit, measured
| Measure | 1 suit | 2 suits (this page) | 4 suits |
|---|---|---|---|
| Player won | 52.8% | 5.7% (5.0–6.5%) | 0.2% |
| Runs completed per game, of 8 | 4.96 | 0.83 | 0.05 |
| Games with 4 or more runs completed | 56.9% | 6.3% | 0.2% |
| Moves in a won game | 117.5 | 154.6 | too few wins to say |
| Deals played | 4,000 | 4,000 | 2,000 |
Two-suit games that our player did win took about 37 more moves than one-suit wins. The extra moves are the cost of sorting: shuffling cards around to get hearts off spades and spades off hearts.
Where it sits among the other games
By our players' results, two-suit Spider falls between Solitaire Turn 3 (10.6%) and Yukon (4.5%). Remember that each game has its own program, and our Spider player is admittedly weak once suits get mixed. So read the 5.7% as "a player who does not plan far ahead and never undoes will lose most games", not as the share of deals that can be won. Published research puts even four-suit Spider at 98.5% winnable when every card is known, so the deals are rarely the problem; the planning is.
Why two suits are so much harder
The rule that changes everything
In Spider, you may put any card on a card one rank higher: a red 7 on a black 8 is fine. But only runs of a single suit move together. With one suit, every run you build is movable. With two, a run like black 9, red 8, black 7 is stuck: you can only lift the cards from the bottom up, one at a time, until you reach a matched pair.
That is why our player's completed runs collapse from nearly five to under one. It keeps making legal builds that later trap cards it needs.
Space is scarcer
Our player cleared a column before its first deal in only 0.5% of two-suit games, against 1.3% with one suit. When it did (21 games), it won 15, about 71%. Small sample, so the range is wide, roughly 50% to 86%, but an early empty column is still a huge advantage.
Two-suit rules on spidersolitaire.us
- Cards: 104, in two suits (on our test, spades and hearts).
- Layout: ten columns, four of six cards and six of five, top card face up.
- Stock: 50 cards, dealt ten at a time, one to each column. Five deals, no reuse.
- Building: any card on one rank higher, regardless of suit.
- Moving runs: only same-suit runs move as a group.
- Empty columns: take any card or movable run.
- Completing: a full King-to-Ace run in one suit is removed automatically.
The game warns you if you deal while a column is empty.
Climbing the two-suit rung
Build in suit whenever you have a choice
If a red 6 and a black 6 can both go on a black 7, the black 6 is almost always the better play. It keeps the run movable. Mixed builds are sometimes necessary, but make them on purpose.
Think of mixed builds as temporary
A mixed run is a parking spot, not progress. Plan how you will unpick it before you commit.
Protect the empty column
With two suits, an empty column is your main sorting tool: park a card, rearrange, and bring it back. Filling it with a random card to "keep things tidy" throws that away.
Use Undo as a planning tool
Our player never undoes and won 5.7%. You have unlimited Undo. Try a line, and if it buries something, step back.
Master one suit first
If one-suit Spider still feels like a coin toss, spend more time there. The skills carry straight over.
Features on spidersolitaire.us
Free, in any modern browser on computer, tablet or phone, with nothing to install and no sign-up, account or email address. Large clear cards and a zoom control, Hint, unlimited Undo, Restart, Auto Play for a finished game, and drag or tap to move. Wins, time and moves are tracked for the current game; sound can be switched off; fullscreen and table colors are available.
Behind the numbers: how we ran the study
The spidersolitaire.us team did this research in September 2026 to measure how much each extra suit costs a player, using the rules our Spider game actually follows.
- Started from the code that runs our game. Same as one-suit Spider except for the suits: any card on one rank higher, only same-suit runs move, 50-card stock dealt in five rounds, any card into an empty column. We assumed, without testing in a browser, that you cannot deal onto an empty column.
- Rebuilt the game in code. The same program handles one, two and four suits; for two suits we used spades and hearts.
- Dealt numbered hands. Deals 100,001 to 104,000. The player's scoring was set using deals 1 to 30, so none of the measured deals influenced it.
- Chose the player. A short look-ahead program that sees only face-up cards and never undoes. It is a floor, and a low one: it is noticeably weaker with mixed suits.
- Played all 4,000 deals to the end.
- Checked the literature. Blake and Gent (2026) report 98.5% winnable for four-suit Spider with every card known. There is no published two-suit figure in that study to compare with ours.
- Calculated the margin of error. For 5.7%, the 95% range is 5.0% to 6.5%.
- Stated the limits. This is how often one particular non-undoing program wins, not how often a deal can be won or how often a skilled person wins. The early-empty-column finding rests on 21 games.
The code behind the ladder
The simulation is in Python 3.11, standard library only, in the spider.py module. Each turn, the player searches up to 250 positions it can reach with the visible cards and chooses the line that scores best: a big reward for same-suit links, a small one for any link, a penalty for each hidden card, and bonuses for empty columns and newly revealed cards. That scoring is why it prefers in-suit builds, and also why it cannot see far enough to untangle deep mixed runs. The 4,000 games ran on 19 worker processes on a 20-core machine in about 14 minutes.
The 95% ranges use the Wilson score method. We had help from Claude, an AI assistant made by Anthropic, in writing and reviewing the code and drafting these paragraphs. It did not supply any figure: all of them come from running the program, and the team checked them against the published study.
Ladder questions, answered with data
Why did my one-suit wins stop at two suits?
Because mixed runs cannot be moved as a block. Builds that were harmless with one suit now trap cards.
Is two-suit Spider harder than Solitaire Turn 3?
For our players, yes: 5.7% against 10.6%. See the Turn 3 page.
Does a two-suit win take longer than a one-suit win?
Yes. Our player's two-suit wins averaged about 155 moves, counting deals from the stock, against 117.5 for one suit.
Is four suits much worse again?
For our player, yes: 0.2%. For people who plan and undo, it is hard but very winnable. The four-suit page has the details.
Can I practice without pressure?
Yes. There is no timer pushing you, Undo is unlimited, and Restart replays the same deal. More games are on the games page.
By Admin, spidersolitaire.us. Research run September 2026.