Hi Meg,

Yes, Picture Gallery is one of my favourite games too! I'm sorry, I don't know what the win rate is, I wouldn't be able to guarantee that every game is winnable I'm afraid. I've tried doing Google searches to see if I can find any other implementations of this game (also known as Gallery Solitaire) but can't find anything that clearly states a win rate for this same implementation.

One thing you could do, without affecting your 100% win rate, is this:
* Take note of the game number of the difficult game (as you have done)
* Restart the current game
* Start a new game
That way, your win rate will be unaffected (newly started games do not count as a loss) and you will still be able to continue to play. At any later time, you can re-enter that same game seed, and the next game you start will be the same difficult game, which you can try again a few more times to see if you can get it out.

Sorry I can't help any more than that.