Starting Thursday, the Idaho State Journal began previewing the top five storylines to watch during Idaho State’s spring football practices, which begin March 29. They are listed in no particular order.

Which base formation will Roger Cooper utilize in his first year as defensive coordinator?

While Idaho State’s offense made noticeable strides last season, the team’s defense was one of the worst in the FCS.

The unit’s raw numbers: 485.8 yards and 35.5 points given up per game. The national rankings: 100th or worse in 10 statistical categories. Only two FCS teams gave up more yards per game than ISU, which ranked 121st out of 123 teams in total defense.

The final straw in the tenure of former defensive coordinator Spencer Toone was a 56-17 blowout loss against UC Davis on senior day. ISU was gashed for 488 yards while the Aggies went 11 of 16 on third down and scored on four of five trips to the red zone. The margin of defeat is the Bengals’ worst at home since 2012.

Toone, who had led ISU’s defense since 2013, was told he would not be retained before the Bengals’ season finale at Weber State. Roger Cooper coordinated the defense for that game and was tapped as ISU’s defensive coordinator in the offseason.

Cooper shared co-coordinator duties with Toone during the 2013 and 2014 seasons, and has coached ISU’s linebackers since 2012.

At his introductory press conference Feb. 8, Cooper said the biggest issues with Idaho State’s defense were giving up big plays and inconsistency.

ISU’s base defensive formation switched from a 4-3 to a 3-4 early last season, following back-and-forth changes between the two base looks over the last few years. Cooper didn’t tip his hand as to which system he would deploy in 2018, only saying personnel would play a large role in dictating that decision.

“Our message overall is going to be: clear, concise and repeat,” Cooper said Feb. 8. “The stuff we run in the spring will carry over into fall camp, and then that will be what we’re running in the games.”

Idaho State’s pass rush was weak last season, and it was backed by a leaky secondary. The Bengals ranked 12th in the 13-team Big Sky Conference and 106th in the FCS with 1.27 sacks per game (14 total), and allowed opponents to complete 63.9 percent of their passes (most since 2010) with 27 passing touchdowns (most since 2003). First-team all-conference linebacker Mario Jenkins graduated, as did defensive tackle JonRyheem Peoples. Jenkins led the team and the Big Sky with 111 tackles, and Peoples was the team’s biggest run-clogger up front at 6-foot-5, 320 pounds.

The Bengals return five key linebackers, including senior Paea Moala, who led the team with 4 sacks last season. Senior outside linebacker Joe Martin finished third on the team with 69 tackles despite missing the final five games with an injury.

Up front, ISU brings back junior defensive ends Chance Salutregui and Rasheed Williams, who had strong freshman campaigns, but tailed off last season. The duo combined for 16 tackles for loss and 9 sacks as freshmen, but just 9.5 tackles for loss and 2.5 sacks as sophomores. In a 3-4, Salutregui and Williams would sandwich senior Treven Aloi. In a 4-3, Aloi would flank junior TJ Togiai. Aloi and Togiai combined to tally 49 tackles, 4.5 tackles for loss and 1.5 sacks in 2017.

On the back end, inexperience has been the Bengals’ biggest burden in recent seasons. Veteran safety Jayson Miller missed all but one game last season, while third-year starting cornerback Anthony Ricks missed seven games. Adkin Aguirre broke out as a playmaker at safety last season, finishing second on the team with 80 tackles and tied for second in the Big Sky with five interceptions. Then-junior cornerback Koby Lowe was fifth in the league with 12 pass breakups and shared starting corner duties with Brandon Monroe, who left the program.

ISU also added six defensive linemen and three defensive backs in this year’s recruiting class.

Cooper has plenty of returning pieces to work with, and first-year safeties coach Jay Staggs may help shore up the secondary. But the road ahead is long and complicated. Idaho State hasn’t ranked in the top half of the Big Sky in total defense since 2005.

“I think the time is right for him,” Bengals head coach Rob Phenicie said Feb. 8. “The kids respect him tremendously. They love him, they love his energy.”