Diplomat: an overlooked two-pack game, and our first measurements of it

Diplomat is a calm, open game played with two packs. Eight short columns of four cards are dealt face up, eight foundations wait to be filled, and the remaining 72 cards form a stock that you turn one at a time, just once. It is a relative of Klondike with a very different feel: nothing in the columns is hidden, but the stock is a one-way journey.

Across solitaire-free.uk we compare our results with published research, especially the major 2026 study by Blake and Gent at the University of St Andrews. Diplomat is not in that study, and we found no other published winnability figure for it. That makes our measurement, as far as we know, the first public figure for this game.

What we found: our computer player, which does not know the order of the stock and never undoes a move, won 47.9% of 2,000 deals.

What we measured

Two things stand out. First, a simple player wins almost half of all games, far more than the same kind of player manages at two-suit Spider (5.7%). Second, even the games it lost were rarely hopeless, since on average it got about three-quarters of the cards home. Because our player is a floor rather than an expert, a careful human with Undo should do better than 47.9%.

The rules on this site

• Two packs, 104 cards. The table starts as eight face-up columns, four cards in each.
• Eight foundations, two for each suit, built up from Ace to King.
• A 72-card stock, turned one card at a time onto a waste pile. There is no redeal: once through and the stock is gone.
• In the columns, build down regardless of suit or colour: any 7 on any 8.
• Only one card may be moved at a time.
• An empty column will take any card.

Playing Diplomat with the numbers in mind

You only see the stock once

With no redeal, every stock card is a one-off chance. Before turning the next card, make every useful move on the table, so that the waste card has as many places to go as possible.

Clear the waste as you go

Our player's scoring deducted a point for every card left on the waste, because a buried waste card is often a lost card. Play from the waste whenever it helps, even if it only buys a little space.

Keep low cards uncovered

Building down in any suit is easy, which makes it tempting to pile cards anywhere. But a 3 sitting under a 9 will not reach the foundation until the 9 moves. Our player was penalised for every card sitting above a lower one, and it's a habit worth copying.

Empty columns are flexible

Any card may fill an empty column, and with one-card moves only, an empty column is the best way to reorder a stack. Clear one when you can.

An early Ace is a coin toss

In 49.2% of our deals an Ace could be played straight from the opening layout. If yours has none, don't worry: the stock holds most of the cards, and the game has plenty of time to turn round.

Diplomat on solitaire-free.uk

Free, with no download, account, sign-up or email address. It works in any up-to-date browser on computer, tablet or phone, with big, clear cards and a zoom control, Hint, unlimited Undo, Restart, Auto Play, drag and drop or tap to move, and wins, time and moves shown for the current game. Sound, fullscreen and table colour can be changed at any time.

For another two-pack game, try Spider. For a single-pack game with a similar layout, see Klondike.

Where Diplomat games go wrong

• Turning the stock too quickly. There is no second pass, so a card turned before the table is ready may be buried for good under the next one.
• Building long mixed stacks. Building down in any suit is easy, but with one-card moves a long stack takes many moves to take apart.
• Filling empty columns with whatever is to hand. Any card may go there, which is exactly why it pays to be choosy. Put a card there only when it unblocks something.
• Forgetting there are two of every card. With eight foundations, a second 5 of hearts can usually find a home later. Don't twist the table out of shape to place the first one.
• Stopping when the stock runs out. Our player got about 76 of the 104 cards home on average, win or lose. Keep working the columns until nothing moves.

How we ran the research, step by step

The solitaire-free.uk team ran this study in September 2026. With no published result for Diplomat, we cannot validate against outside research, so we set out the method in full.

1. Rules from our code. 104 cards, eight face-up columns of four, a 72-card stock turned one at a time with no redeal, building down regardless of suit, single-card moves only, any card to an empty column.
2. A program version. We rebuilt Diplomat in Python with a computer player.
3. Numbered deals. Deals 1 to 2,000, each shuffled from a numbered seed so the same games can be dealt again.
4. The player. It does not know the order of the stock, just as you don't. Before each move it looks up to 300 positions ahead over the table and the waste, then plays the most promising line. It turns the next stock card only when nothing on the table improves its position. It never undoes, so its result is a floor.
5. Running it. 2,000 deals.
6. Published comparison. None exists that we could find, including in the St Andrews study. There is nothing outside our own work to test this figure against, and we say so plainly.
7. The margin of error. A 95% range is where the true value very probably lies: for 47.9%, between 45.7% and 50.0%.
8. What the figure can't tell you. It is not how many deals can be won with perfect play; we did not build a solver for Diplomat. It is how often a sensible, no-undo player wins.

Behind the numbers: the code

We used Python 3.11 with its standard library and nothing else. Diplomat has its own module, diplomat.py, and a shared runner ran the 2,000 deals across 19 worker processes on a 20-core machine in about fourteen minutes. The player's look-ahead scores each position by cards on the foundations, cards resting on a lower card, correctly linked cards, empty columns and cards left on the waste, and plays towards the best. The stock order is hidden from it throughout. Ranges for percentages use the Wilson score interval; the averages use a normal 95% interval.

We had an AI assistant, Claude from Anthropic, help write and review the simulation code and draft this page. The AI is not where the figures come from: every number was produced by running the code, and the team reviewed the results before they were published.

Frequently asked questions

How often can you win at Diplomat?

Our no-undo computer player won 47.9% of 2,000 deals. A careful human using Undo should do better. We know of no published figure for perfect play.

Why does Diplomat have eight foundations?

Because it uses two packs: each suit appears twice, and each copy is built up separately from Ace to King.

Can I go through the stock again?

No. On this site the stock is turned once only, which is why every card counts.

Why can I only move one card at a time?

That is part of Diplomat's rules here. It makes empty columns especially valuable, because they let you rearrange a stack card by card.

What else should I try?

Golf, where our solver found 92.7% of deals winnable. For a two-pack challenge, try two-suit Spider. See everything on the games page.

By Admin, solitaire-free.uk. Study date: 18 September 2026.