i think Leslie Frazier deserves a lot of credit for closing out those close wins. I was thrilled when he was hired and he's been an excellent coordinator this season.
One reason we get those last drive interceptions is because we are properly executing the 'prevent'/zone defense. We have players in position where the QB has limited options and when he does throw, we are in position to intercept. Turnovers aren't always luck, they are often helped by the design of the coverage. We have an excellent DC and a great secondary.