During your new hire class they will release a vacancy bid for your new hire bases. You will be awarded your base by seniority in your class (by age) and the rest of the system just like any other pilot. Your first two weeks to a month and a half will be spent in your IOE base, which is awarded by preference and availability via a sign up preference sheet. How long you are there depends on where you fall in the month and how long your IOE trips take. The remainder of your flying after IOE will be cobbled together from flying in the open time inventory. Once you get to your awarded base, you will be on weekend reserve.

Planning routinely shuffles pilots around by increasing and decreasing base sizes due to schedule shifts. Sometimes this results in big vacancies for various bases. In this case, new hires have gone to MCO, HOU, BWI, LAX, PHX, and yes, OAK. In our current low hiring situation, I would suspect the majority will end up in either BWI or LAX. That's just me spitballing, though. OAK is pretty mature as a base and most of the people there are there because they chose to be there.