J, 37 (or 0; see below) characters
(i.5)A.(52$'cdsh'),.4#'kqajt98765432'
For a much better view, prepend ,"2 and change the suits to uppercase. For an even better view, prepend ,"2' ',"1 instead. For more decks, change i.5 to a higher value, up to at least 24 factorial (6.2*10^23).
The trick here is twofold: Make the piles solid (enough) with (enough) aces built safe within, and to do that easily. If we deal the standard unshuffled deck, there is one rank that is never exposed. Let's move the aces there. There are several possible moves depending on the color assignment, but in order to prevent exposing the easy ace, order the colors such that this move is not possible. We are dealt this tableau (black colors in uppercase):
kC kd kS kh qC qd qS
qh aC ad aS ah jC
jd jS jh tC td
tS th 9C 9d
9S 9h 8C
8d 8S
8h
The only moves possible are
qh-kC exposing kd
tS-jd/jS-qh freeing diamonds up to 8d (if the stock is good)
8h-9S exposing 8S
8d-foundation/9h-tS or 8d-9S/9h-tS exposing 9C.
When these moves are performed, we're left with this solid tableau:
kC kd kS kh qC qd qS
qh aC aS ah jC
jS jd jh tC td
tS th 9C 9d
9h 9S 8C
8h 8S
The eight of hearts can be moved between the two black nines and the cards from the deck can be stacked on top, but no more aces can be freed.
Now, we can replace 8h, 8S and even 8h with a different card in the the stock and the game stays unwinnable. This pushes the number of known unwinnable decks up to 27! at least. Removing 8C opens up additional moves, but I believe the game is still unwinnable.
Note that if merely discovery is sufficient, then my score is zero as I didn't need a computer to verify the unwinnability of these 27! decks.
Solutions to Solitaire Dreams - Creating a winnable solitaire starting hand could be edited into solutions to the core of this with one character change, and making them repeat 5 times doesn't add anything.
– Peter Taylor – 2013-08-21T07:38:16.803@PeterTaylor given that the only answer given to the duplicate question is also a cheating one, I don't think it is obvious this is actually a duplicate. – John Dvorak – 2013-08-21T07:53:24.867