I doubt you have read the PBS guide or manual. If you had, you would know that the PBS DOES apply your preferences and only at the end of the process, if a minimum of flying is not covered then things get unstacked but your avoid pairings and days off ARE respected - at least initially. If you want help bidding - I'm very junior yet got EXACTLY what I wanted, and my desires are very specific - message me here and I'll give you a hand. The pool of pairings is so large compared to the number of pilots, that there is no reason you can't get close to what you want to have.