A Microsoft FreeCell deal number is a reproducible shuffle identifier. The same number, passed through the same pseudorandom generator and dealing algorithm, creates the same 52-card layout. That made it possible for players to share a difficult position by number rather than describing every column.

Microsoft shipped 32,000 numbered deals originally, and later builds raised that to 1,000,000. Cards4.net applies the same generator to a wider range, accepting Microsoft-compatible numbers from 1 through 32,000,000 using the ?ms=N query parameter. Only the 1–1,000,000 span has been studied for impossible deals; the numbers above one million are a Cards4.net extension of the same algorithm rather than a Microsoft-published range.

How a deal number creates a layout

The number initializes the historical Microsoft-style linear congruential generator. Each step updates a 32-bit state:

state = (state * 214013 + 2531011) mod 2^32
value = (state >> 16) & 0x7fff

The shuffle uses each generated value to select a card from the remaining deck. The selected card is emitted, the last remaining card fills its position, and the remaining count decreases. This is the shuffle used by Jim Horne's Microsoft FreeCell implementation for Windows. It is deterministic rather than cryptographically secure, which is exactly what numbered-deal compatibility requires.

Cards are then dealt left to right across eight columns. Columns 1-4 receive seven cards and columns 5-8 receive six. Using the same number with a compatible implementation reproduces the same opening position.

The original 32,000 deals

The first 32,000 deals became the best-known reference set because players and solver projects could divide a finite, shared collection. The Internet FreeCell Project found solutions for 31,999 of them. Deal #11982 was later proved impossible: no legal move sequence clears it.

This result is why "almost every FreeCell deal is solvable" is a better statement than "every FreeCell deal is solvable." In the original set, the exact count is 31,999 out of 32,000.

The eight impossible deals in the first million

The known impossible deals from 1 through 1,000,000 are:

#11982, #146692, #186216, #455889, #495505, #512118, #517776, and #781948.

That leaves 999,992 solvable deals in this numbered range. The ratio describes the Microsoft-generated sample; it does not prove the same frequency across all mathematically possible FreeCell arrangements or across later number ranges.

If you are stuck on one of those eight numbers, more Undo will not produce a solution. On another deal, reconsidering cell usage and the order of column moves is normally more productive than assuming the layout is impossible.

Loading a deal on Cards4.net

Append a lowercase ms parameter to the localized or English FreeCell URL:

The parameter name is case-sensitive, so use ms, not MS. Zero, negative values, decimals, nonnumeric text, and numbers above the supported range are ignored by the client.

Cards4.net shows the active Microsoft number above the board. Share the full URL to give another player the same starting position.

Numbered deals versus Cards4.net seeds

A Microsoft number and a normal Cards4.net seed are separate systems:

  • Microsoft-numbered mode reproduces the historical algorithm and may include an impossible deal.
  • Random mode uses Cards4.net's seeded shuffle and makes no solvability promise.
  • Solvable Mode and daily challenges use Cards4.net seed libraries whose entries have a solver-found winning line.

The daily FreeCell challenge therefore does not draw from ?ms=N. Every player receives the same prevalidated daily deal for the UTC date, but it belongs to the Cards4.net seed system.

Deal number does not indicate difficulty

The number is a generator input, not a rank. A larger number is not necessarily harder, and adjacent numbers do not create similar layouts. Deal 11982 is impossible because of its card structure, not because of its place in the sequence.

Difficulty also differs from winnability. A solver may prove that a path exists while a person still finds the required order difficult. Use numbered deals to repeat analysis, compare solutions, and share exact challenges rather than as a universal difficulty scale.

FAQ

What are the eight impossible Microsoft FreeCell deals in the first million?

They are #11982, #146692, #186216, #455889, #495505, #512118, #517776, and #781948. The list applies only to the first million Microsoft-numbered deals; Cards4.net's extended 1–32,000,000 range has not been fully studied, so it should not be generalized beyond that range.

How do I load a Microsoft FreeCell deal on Cards4.net?

Open /freecell?ms=N and replace N with a number Cards4.net supports, from 1 through 32,000,000. For example, /freecell?ms=617 loads deal 617, and /freecell?ms=11982 loads the impossible deal 11982.

Is every Microsoft FreeCell deal solvable?

No. Deal #11982 is the only impossible one in the original 32,000, and eight impossible deals are known in the first million. The generator, shuffle, card ordering, and dealing layout are all deterministic, which is why the same number reliably reproduces the same layout.

Does the daily FreeCell challenge use Microsoft numbers?

No. Daily challenges use Cards4.net's separate prevalidated seed library rather than ?ms=N.

Can I share a numbered deal?

Yes. Share the full /freecell?ms=N URL and the recipient will receive the same starting layout.

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