The card on the left pile, when moved to the right side will go under the top card (the top card being one of a pair used to clear a pair on the board and somehow remains there but not able to move or play again) and therefore the card moved can not be clicked to use in upper board. I have even had it glitch once in a while. When I do that, it gives me only the score of what I have cleared, with no calculations. I get a lot of those hands where it is impossible to finish and I just quit the game. Just not always as I think either at the time. I don't seem to notice it as a subtraction at the time. It doesn't always seem like it works right or even makes sense. Then at the end (if you clear all) it does a calculation of how long it took and cards left in the deck and the ones you cleared and whatever else it may do. It does seem weird But as you play you will see your score adding up as you clear cards.
