Raiders' Trayvon Mullen established himself as long-term cornerback answer

Raiders' Amik Robertson is motivated by family, strengthened by adversityIn the past, the Raiders have invested heavily in the cornerback position with little to show for it. Previous general manager Reggie McKenzie tried in vain to end a series of stopgap solutions at the position, paying Sean Smith eight figures per season in free agency. Waiver claim David Amerson turned one big season into a contract extension, with Smith and Amerson set to earn just under $75 million combined over the life of their deals.

The Raiders, it turned out, still were not set at the position. Neither played out their entire contract. Amerson was around for half of that deal, Smith lasted the same span after…