Spider Solitaire with four suits: a deal you can't judge by its cover

Four-suit Spider is the full game: two complete packs, all four suits, 104 cards. The opening looks just like the easier versions — ten columns, 44 of 54 table cards face down, 50 in the stock — but now only a run in a single suit can move, and the chance of finding one in the bottom row is small.

Here is the paradox that makes this game so interesting. When a computer is allowed to see every card, published research finds 98.5% of four-suit deals can be won (Blake & Gent, 2026). But our own player, which only sees face-up cards and never undoes a move, won just 4 games out of 2,000 (0.2%). Almost every deal is winnable; almost none are won by playing blind.

So the opening deal is not the thing to judge. The thing to judge is how well you use the information you uncover. That's what this page is about.

Four-suit Spider, by the numbers

The contrast between the first two rows of results is the whole story: the deals are generous, but you need memory, planning and Undo to collect.

Four-suit Spider on klondike.nz: the rules

The table

Two full packs shuffled together. Ten columns — four of six cards, six of five — with only the last card face up. Fifty cards make the stock.

What counts as a win

Eight complete runs, King down to Ace, each in one suit. Finished runs are removed automatically.

Moving cards

• A card may be placed on any card one rank higher, of any suit.
• Only runs of a single suit, in sequence, move as a group.
• Any card or suited run may fill an empty column.
• The stock deals one card to every column, with no redeal. The game warns you if a column is empty when you deal.

How to read a four-suit game as it unfolds

Treat each uncovered card as news

With 44 hidden cards, the start tells you little. Every time a card turns over, update your plan: which suits are clustering, which Kings are showing, which columns are shortest.

Prefer same-suit moves above almost everything

At four suits, a mixed stack can take a long time to unpick. When you have a choice between two moves that both uncover a card, pick the one that keeps a suit together.

Chase the short columns before the first deal

Emptying a column before dealing happened in only 6 of our 2,000 games — but the player won 2 of those 6, against 4 wins in all 2,000. It's a tiny sample, so treat it as a hint rather than a law: early space matters.

Use Undo as a way of looking

The biggest gap between our player and the 98.5% ceiling is information. Undo lets you peek at what a move uncovers and change your mind. That is legitimate, and it is how people actually win this game.

Expect long games

Four-suit wins take many moves. Our player's four wins averaged about 209 moves, though four games is far too few to generalise from.

Where four suits sits on the difficulty scale

On the same deals-and-player set-up, our player won 52.8% at one suit, 5.7% at two suits and 0.2% at four. Its completed runs per game went from about 5, to under 1, to almost none. solitairex.io puts four-suit Spider in its "expert" tier at 11% or less for real players. Try two suits first if four feels like a brick wall.

A first-minute checklist for four-suit Spider

With four suits, the opening tells you very little, so this checklist is about how to handle the first twenty or thirty moves rather than how to judge the deal.

1. Find any same-suit pair in the bottom row. With four suits these are scarce, so each one is worth taking.
2. Uncover before you tidy. Most of the table is hidden. A move that turns a card over is usually worth more than one that makes a stack look neat.
3. Keep mixed stacks short. Every card of the wrong suit in a run must eventually be moved off it.
4. Work towards one empty column before the first deal. It is rare — 6 of our 2,000 games — but nothing else gives you as much room to sort.
5. Don't deal while you still have useful moves. The stock is five deals of ten cards, and each one covers some of your work.
6. Accept that some games will stall. Even with 98.5% of deals winnable in principle, many will beat you in practice. Undo, try a different line, and learn which choices mattered.

Playing four-suit Spider here

Free in any modern browser on a computer, tablet or phone. No download, no sign-up, no email. Large, clear cards with zoom; Hint, unlimited Undo, Restart and Auto Play; drag-and-drop or tap; wins, time and moves for the current game; sound off, fullscreen and table colours. One for a long winter evening in Queenstown.

Where these numbers come from

The klondike.nz team ran this study in September 2026.

1. Rules from our code. Four suits, one stock card per column, no redeal, suited runs only. We assumed you can't deal with a column empty, following the game's warning; this wasn't confirmed in a browser.
2. A program version. The same Spider engine used for one and two suits.
3. Numbered deals. Seeds 100,001 to 102,000, separate from the deals used to tune the player.
4. The player. Sees only face-up cards, never undoes.
5. No solver of our own. We did not build a four-suit solver; for the ceiling we rely on the published 98.5%.
6. Running it. 2,000 games.
7. Error bars. 0.08–0.51% is the 95% range around our 0.2%.
8. Limits. The player is very weak at four suits. Its figure is a floor far below what people achieve.

Under the bonnet

The code is Python 3.11 with only the standard library, in spider.py, with a shared runner that farms the games out to 19 worker processes through multiprocessing. The four-suit run took about three and a half minutes. Each turn the player runs a 250-position best-first look-ahead over visible cards, scoring same-suit links, empty columns and newly uncovered cards. We report Wilson score 95% intervals. An AI assistant, Claude from Anthropic, helped write and review the code and draft this text; it did not generate any figure — the numbers are the code's output, set against the published research.

Questions players ask

Can four-suit Spider really be won most of the time?

With perfect knowledge of every card, yes: published research puts it at 98.5%. In practice it's far harder because you can't see the hidden cards.

Why did your computer player almost never win?

It can't see hidden cards, has no Undo, and its look-ahead is short. It shows how hard the game is to play blind.

Is a deal with suited pairs showing a better deal?

It helps you start, but with 44 cards hidden it says little about the outcome.

What should I play if four suits is too tough?

Drop to one suit or two, or try classic Klondike.

By Admin, klondike.nz. Study date: 18 September 2026.