We have to figure out what would cause a vacancy.

How many retirements? How many 757s coming? Will freight fall off after peak or stay up?

If the 757 keeps taking Airbus cities then the lateral moves will continue. More than a few 727 CAs and widebody FOs have to upgrade to create secondaries for 727 FOs and SOs to fill.

I see a vacancy for ANC. They draft too much and the MEM bidpack is nearing normal line averages. They may eventually want to stop building ANC HSBYs for MEM based crews. But see question #3.