Here’s one for airline pilots out there:
If you fly a trip schedule that is 4 days long how common is it that you would or would not pass through your domicile city during the course of the trip schedule (prior to your last flight of the trip)?
It depends on the airline, seniority, and domicile.
For example, it is distinctly possible that a low seniority UA 767 FO based in DEN could spend the entire trip flying trans-atlantic from ORD and IAD, while it is almost assured that a PHX-based US Airways West A320 captain would pass through PHX at least once a day.
Every airline is going to be different as drdisque stated. What is the deciding factor is the schedule you choose/assigned that you are able to select based on your seniority that you can hold.
With that being said, many pilots that commute intentionally pick routes that do not travel to their domicile because then they will have to have a crash pad and are not paid per diem. If they overnight elsewhere, they get a cozy hotel room and out-of-domicile pay.