I've seen various versions of the rules of "Baker's Dozen" (e.g. on about.com, Wikipedia) stating that the rule for kings is simply that they are placed to the bottom of the column they end up in.
But in the version given by Sheila Anne Barry in Great Card Games for One, it is stated that "If a King is lying on another card of the same suit, place it underneath that card".
Does anybody know of another source for that rule, and/or have any notion of which variant is most popular?
Given the game limitations caused by Barry's variant, and the vast number of resources that can be found contradicting her, I would think that the common rule is to place Kings at the bottom of columns.
You could do an exhaustive internet search for Baker's Dozen rules and never see the variant that Barry describes in her book. Other books, such as Hoyles, also follow the rule that Kings go to the bottom of a column. It seems that Barry is alone in her variation, and I think that's because it makes a more difficult game.
For the common rules of Baker's Dozen, "once all cards are taken out of a column, the column can never be filled." The reason you move all Kings to the bottom of columns is to ensure that the game is potentially solvable. If you don't move Kings to the bottom, they'll likely sit on top of differently suited cards and you'll have to clear the entire suit of that King before being able to start on the suit or suits it's covering.
For example, if you deal a tableau and it has a column (bottom to top) {2D} {7H} {9C} {KC}, under the common rules you'd rearrange to {KC} {2D} {7H} {9C}. In this case, you'll have a fairly easy time building up your columns and foundation piles. But in Barry's variant, you'd rearrange to {2D} {7H} {KC} {9C}. Before you can even move the two of diamonds and seven of hearts, you have to clear the entire club suit to the foundation piles. This gives you far less maneuverability over the course of the game.
It's possible you can get into a similar situation using the common rules, although the implications aren't as severe; you could have a pile that looks like {2S} {6D} {JC} {QS}, so you need to move the Queen and Jack in order to get to the lower cards. But with the common rules, there will be a King somewhere to move those cards to. If Kings aren't at the bottom of columns, and there is never anywhere to move them because columns can't be reused once depleted, then cards can get stuck beneath them until that King's suit is cleared.
I haven't found a copy of Barry's book, but there is the possibility that she allows cards to be moved into empty tableau spaces, like in Spanish Patience. If that's the case, then her description would seem to fall somewhere between the two games. It would also negate the difficulties caused by allowing Kings to sit above other cards.
