"On an island."
That is what life is like as a defensive back, especially a cornerback.
When the D-back in question messes up, it usually means a big gain for the offense and the back in question becomes the goat.
When he does his job, more often than not, nobody pays attention to him because the ball goes nowhere near him.
That is something one notices when looking at the careers of the best defensive backs. Their statistics seem to deflate as their career progresses.
The thing is, it is not so much a matter of the back in question playing more poorly, but of the opposing offenses simply avoiding his part of the field.
If a cornerback is All-Conference caliber, then the opposing quarterback will simply throw the other way. If a team has two strong and highly instinctive safeties, then the quarterback will avoid throwing over the middle.
In a way, if a defensive back seems to have a dearth of statistics in his senior year, then it is probably a safe bet that the back in question did a good job.
As has been the case with the previous installments of this series, this list is not about "talent," per se. Rather, it is purely about on-the-field productivity and presence. In effect, a one-and-done player simply produced less over a period of time, and thus, probably got less consideration than a three-year starter.
Moreover, what the player did after graduating is of no concern to me. I am only concerned with what the player in question did on the gridirons of the Big Ten.