To recap: I posted the notion that all games are potentially winnable above and some have had their doubts about this.
To be sure that never occurred to me either until this last run of more than 100 straight games. I was defeated at 28 in a row by what seemed to be an impossible-to-win game and again at 44 in a row the same way. But this time I got a monstrous deal at 59 in a row and was determined to reach 60 to beat it. When I did (after some 4,000 moves) I began to suspect that every game was winnable and this notion proved to be a great aid to winning in spite of further apparently impossible deals…and kept working. The trick to winning really difficult hands is to do something weird, like–as I wrote above–putting the 5 of clubs on the 6 of hearts instead of the (more obvious choice) of the 5 of hearts…or even not moving a card when you could!
I don’t know for sure that every game is winnable; I just suspect it.
To answer madsircool (who pointed out the apparent contradiction of restricting started games to say 3 in a sequence if all games are winnable, I did emphasize that the starting strategy was intended to reduce the frequency of almost impossible games. 4,000 moves is awfully tiring.
And as for those who shun the use of Undo: entirely understandable. It depends on how you get your jollies when playing. I find that the Advanced game presents quite enough challenges to make it fun (1,000 moves or more is quite common) even with Undo and I don’t enjoy the idea of being defeated by the pure chance of whether at each move, I turn over card A instead of card B. There’s just too much luck involved in that–although I think that strategy might be better at making the Intermediate level more challenging.