The Dolphins, Tannehill, and the eighth overall pick

The Miami Dolphins haven’t had a franchise quarterback since 1999, the final year of Dan Marino’s Hall-of-Fame career.  Since then, they’ve invested five second-round picks in the quest to find one — via trades for A.J. Feeley and Daunte Culpepper, and by putting the names “John Beck” and “Chad Henne” and “Pat White” on their…