These days new-hires are getting JAX/TPA right away. ROA/ORF seem to be the most Jr. bases. Some guys are sitting reserve in JAX for up to 9 mos. Hopefully, that time will diminish as we bring more people on-line. Jax used to have the best lines, but now TPA's are better. It seems to revolve every few months. Good luck!
All you have to do is change your bid monthly. If you wanted to change every month, if there was an opening in the base and you had the seniority to hold it, you could. moving would get a little expensive but hey, more power to ya.