On occasion a new category will go junior on the initial bid, while the senior pilots sit on the sideline. Senior pilots will dog pile on top as the category grows and they get a better sense of where they will fit in as it stabilizes. I was at 75% of a new category and for the next three AEs watched as senior pilots filled EVERY vacancy. To make matters worse, some junior pilots bid out and the contingent vacancies were also filled by senior pilots. It got me into a category I wanted, but my relative seniority slid about 12% before finally recovering to my initial bid threshold. Bid what you want, want what you bid.