Eight Off: same-suit discipline, and plenty of room to plan
Eight Off asks you to build in suit, like Baker's Solitaire. Only a King may enter an empty column, and all 52 cards are visible. The difference is that you get eight free cells, and four of them start with a card already in them. That extra space is room to think. Room to think is what turns strict rules into a game where almost every deal can be won.
We let a solver play 10,000 deals on this site's rules. It won 99.9% of them (9,989 of 10,000; 95% range 99.8%–99.9%) and proved the other 11 deals impossible, leaving none undecided. Every card is visible, so this is the true share of winnable deals. Good play wins almost all of them.
We did not run a greedy player on Eight Off, so there is no greedy-versus-planner pair on this page. What we can show is the difference one rule makes: being able to move a whole same-suit run in one go, rather than card by card.
At a glance: what group moves add
| Version | Solved | Proven impossible | Undecided | Deals |
|---|---|---|---|---|
| As played here: same-suit runs move together | 99.9% (99.8%–99.9%) | 11 deals (0.1%) | 0 | 10,000 |
| One card at a time (published rule set) | 99.8% (99.7%–99.9%) | 14 deals (0.1%) | 6 deals (0.1%) | 10,000 |
| Baker's Solitaire: same suit, only 4 cells | 31.8% (30.9%–32.8%) | 68.2% | 0 | 10,000 |
Group moves rescue only a handful of deals; the game is already very open. The big jump comes from the cells. Baker's has the same suit rule and the same Kings-only gaps with four cells, and only 31.8% of its deals can be won. Double the cells, and the game goes from mostly impossible to almost always winnable. Free space is planning space.
Eight Off rules on this site
- Deck: one standard deck, all 52 cards face up.
- Tableau: eight columns of six cards.
- Free cells: eight; the four cards left after the deal start in four of them.
- Foundations: four, one per suit, Ace to King.
- Building: down by one rank in the same suit only.
- Empty columns: a King, or a same-suit run headed by a King.
- Group moves: a same-suit run moves as a unit if it fits: empty cells plus empty columns, plus one.
How a planner plays Eight Off
Start with the pre-filled cells
In 28.1% of deals (95% range 27.2%–28.9%) at least one Ace starts in a pre-filled cell. Every card you play out of a cell gives you back working space. Clearing the cells early is the best early move in this game.
Send Aces up at once
In 66.4% of deals (95% range 65.5%–67.4%) an Ace can be played immediately, from a column or a cell. Because building is in suit, a foundation move in Eight Off never hurts you.
Build only same-suit links
A card placed on a different suit can only leave through a cell. Think of every same-suit link as progress and every mixed placement as borrowing space.
Keep two cells in hand
Eight cells tempt you to fill them freely. Each empty cell adds one card to the run you can move, so a full set of cells means single-card moves only. A greedy player fills cells to make a move possible now. A planner keeps them for the move that needs them later.
Line up a King before emptying a column
Only a King can use the gap. Clear the column when a King is ready to move in, not before.
Wins are short
The solver's first solution averaged 35.5 moves (95% range 35.3–35.7, over 9,989 solved deals). A clear plan executed cleanly beats long shuffling.
Eight Off on spidersolitaireonline.us
Eight Off is free in any modern browser on computer, tablet or phone, and needs no account or download. Restart replays the same deal so you can look for a cleaner line, and Undo is unlimited. You also get Hint, Auto Play, large cards with zoom, drag or tap to move, a counter for wins, time and moves, and settings for sound, fullscreen and table color.
How we ran the study
The spidersolitaireonline.us team ran this study in September 2026 on this site's own Eight Off rules. The simulations are written in Python. An AI assistant, Claude by Anthropic, helped write and review the code and draft this page. Every figure comes from running the code.
- Rules traced in the site code: 48 cards in eight columns, four in cells, same-suit building, Kings only in gaps, group moves up to empty cells plus empty columns plus one.
- Two versions: the site rule, and the one-card-at-a-time rule used in published research, so we could check our work.
- 10,000 numbered deals for each version, seeds 1 to 10,000.
- A solver. Every card is visible, so a search for a winning line gives a true answer. Each deal got up to 200,000 positions, and every site-rule deal was settled within that.
- Published check. Blake and Gent (2026) estimate 99.8805% for the one-card version. Our one-card run gave 99.8% solved with 14 proven impossible and 6 undecided, which is in line with theirs.
- Margins of error are 95% Wilson score intervals. Our deal numbers are our own seeds.
Eight Off questions
Can I win every deal?
Almost. Only 11 of 10,000 deals were proven impossible on this site's rules.
Why are four cells already full?
Six cards go to each of eight columns, which is 48. The four left over start in cells.
How is it so much easier than Baker's?
Four extra cells. Same suit rule, same Kings-only gaps, yet 99.9% of deals can be won here against 31.8% in Baker's.
Does it help with Spider?
Yes. Thinking only in same-suit runs is the core skill of multi-suit Spider. Also try FreeCell and Baker's Solitaire, or browse from the home page.
By Admin, spidersolitaireonline.us (Solitairen OOD). Research run September 2026.