Understanding training patterns for Stratix-II deserializer DPA

I believe DPA run length is the max number of cycles of a constant value can occur before loosing lock. As for a training pattern, I've heard pretty much anything with transitions will work, but with fewer transititons it may just take longer. It is not looking for a pattern though(such as 10-bit comma), just transitions to figure out where the data changes and where to center the clock. There is no word alignment occuring, as that has to be done by you.