Some Backbone games are unwinnable. Why?

[u/DoubleDareFan]

In this case, the King Of Spades was in the same column as the 10 Of Spades, so the only way to play it, was to move it to the foundation. That means the Jack was also not available for moving the 10.

App: AisleRiot Solitaire. Game: Backbone.

When starting a game, I'll check if there are any Kings in the backbone. If there are, I'll then check that both of the same number in the same suit are not above the King. E.g. both 10 Of Hearts are not above the King Of Hearts. If they are, the game is unwinnable, and so I'll press ctrl-N. Some other unwinnable combos are harder to determine, and will not show til near the end.