You can select your preferential bids for every fleet and seat from number one to number xyz as many times as you want. If your seniority can hold it you get the bid. Biggest mistake people make is not keeping their preferences current. You may be awarded a bid you really wanted, then forget to upgrade your preferences. Then zap, you get a bid you failed to remove when seat locks are gone or released. Bottom line, all seniority based. No preferential knee pad bid awards.