Massive prevalence of early report/late release, high legs per day with mandatory plane changes at every hub (and some "outstations") with both mad dash panic 5 concourses away scrambles or 3-4 hour sits, relatively short rests with circadian cycle shifts, etc.

Its no one thing, or even just several things, but the relentless application of all those things. Its so bad in some BES's that even living in base is barely a mitigating factor for just the report/release part of it and nothing else.

The only way it gets fixed at this point is if we pry it out of their cold, unplugged optimizer at contract time. Better work rules including RCC leverage with teeth. Lip service mea culpas about "running it a little hot" won't fix it.