A new era of  Boise State  football is just around the corner.  After capturing three straight Mountain West titles with a College Football Playoff berth in 2024, the Broncos are leaving the MWC for the  Pac-12  alongside Colorado State, Fresno State,  San Diego State  and Utah State on July 1.  Boise State Broncos On SI  is taking a look at the five biggest questions for the Broncos ahead of their  2026 opener at Oregon . We kicked off the series with a breakdown of the rebuilt receivers room and will now take a look at Boise State’s retooled secondary.  4. What will the defensive back rotation look like? Boise State’s secondary morphed from a weakness into a strength in 2025.   During the Broncos’ CFP run in 2024, Boise State ranked No. 106 nationally at 241.4 passing yards allowed per game. With largely the same personnel, the Broncos jumped to No. 15 last season at 175.6 passing yards allowed.…