Rookie pools are determined after the draft is over. Each team is given a pool based upon no. of picks, what rds, and position within each rd.
Peters 2009 salary was $3.8 million after playing time and Pro Bowl incentives were added. His remaining amortization is $2.1 million (2009 & 2010). Due to the presence of an uncapped 2010, all remaining amortization is accelerated onto League Year of trade regardless of the date of trade. His cap number for 2009 was $4.9 million. Subtract the $2.1 million and you get a cap savings of $2.8 million minus the salary to make it "top 51" compliant. So, Bills saved approx. $2.4 million on 2009 cap ($3.85 million cash to cap)