Because the only difference between the two games (regular and thoughtful) is the knowledge of card location, all thoughtful games with solutions will also have solutions in Klondike. Since any winnable Klondike game must necessarily be winnable when played thoughtfully, the results on Thoughtful Klondike tells us that 82% is an upper bound on the winnability of regular Klondike when we don't know the location of all cards. The true probability with best play might be much smaller, because the difference between a right and wrong move cannot be known in advance whenever more than one move is possible and some cards are still hidden. Ultimately, very little is known about the winnability of regular Klondike. It has been estimated that according to probability a skilled player can expect to win at least 43% of games, but this gives a massive gap of almost 40% between that number and 82%.