So how do Pro Bowl-caliber players go undetected until late in the draft? In part, it's because assessing college players' N.F.L. potential is very difficult. Collegiate success is no guarantee in the N.F.L.; offensive and defensive schemes vary widely; and, unlike in baseball or basketball, there are relatively few games in a college season, which means there are fewer observable events for scouts. Financial considerations play a role too, since teams invest more money in earlier picks. What this adds up to is uncertainty, especially after the first round. Some early picks turn out to be duds ( Ryan Leaf or JaMarcus Russell , anyone?), while Brady, Terrell Davis and other Pro Bowlers wait until the sixth round. Brady may be the best sixth round pick in N.F.L. history, but there are more than a dozen Pro Bowlers who were picked later than he was. Chances are the 2013 will have a few, too.