As the fate of the Bears franchise rests on their ability to find a franchise quarterback, it is easy to question a general manager who has missed at the position so often. But history suggests Ryan Pace has as good a shot at finding the team’s first franchise quarterback in more than 50 years as anyone else does. Because if there is one thing that can be gleaned from studying how some of the best franchises in the NFL have obtained their leading signal callers, it’s simply that finding quarterbacks is an inexact science that can have many misses before a big hit.