The eleven month rule should not be applied as a hard and fast rule. One must be careful to avoid picking a holiday period 11 months out, as Amtrak may not have assigned any rooms to the lowest bucket for the days leading up to and trailing the actual holiday. Additionally, if the 11th month is June, July, or August, I would again not recommend using those prices as a basis for determining the lowest bucket as Amtrak again doesn't always price any rooms at the lowest bucket price.

The best source for knowing the lowest bucket price can be found in the Amtrak timetable on page 116 of the newly released timetable. Of course if you aren't traveling between endpoint cities listed on that page, then you'll have to guess at what the lowest bucket might be from your departing/arriving points. But using that table in the timetable, in conjunction with the above suggestion of pricing months ahead, you should be able to get a good idea of what the lowest bucket should be.