you can be sure of your base if you are in the top 10% of seniority at the company or if you bid into a newly established route ie. The guys going to the STL flying are protected for 2 years & and when ALB flying was awarded those guys had a 2 year protection as well. Base protection is a heated topic these days!
A few of the Caribbean guys got bumped from their bases (guys that have held bases for a couple years), by senior people from the north for the winter season there has a been a bit of an outcry lately.