At the end of the 2017 college football season, Colorado State fans found themselves wondering what could have been. A promising season turned mediocre, due in part to shoddy defense down the stretch.

Look no further than their game against Boise State during which the Rams conjured up 52 points but failed to secure a win, conceding 59 to the Broncos in the overtime loss.

Despite ranking 11th in the nation in total offense at just under 500 yards per game, CSU secured its third consecutive 7-6 season culminating in a bowl game defeat. To complicate matters further, CSU graduated five starters on defense and three more players who saw significant playing time.

The defense needed an overhaul during the offseason, and the Rams have done just that.

CSU welcomes an entirely revamped staff on the defensive side of the ball as all four defensive specialty coaches from 2017 are no longer in the picture. Led by defensive coordinator John Jancek, CSU hired four new defensive coaches while promoting one.

Keith Gilmore (defensive line), Eric Lewis (cornerbacks) and Chase Gibson (linebackers/special teams) will join Jancek in their first year with the program while former defensive quality control coach George Helow will serve as the safeties coach to round out the five-man defensive staff.

Though they are entering new positions at CSU, the familiarity of the staff members is unique. Nearly all coaches have either crossed paths with each other or Bobo during a previous coaching stint, offering a rare combination of experience and comfort. That familiarity suited Jancek and Bobo well during the hiring process.

“You got to ask questions of each coach to find out how similar they are or how similar they’re not to each other,” Jancek said. “That was extremely helpful to be able to pair up with a lot of like philosophies in terms of how we play certain run plays, how we play coverages.”

After finalizing the staff, the coaches turned their attention to recruiting the talent on the field. Of the 23 players that signed into CSU’s 2018 recruiting class, 14 come on the defensive side of the ball. That defensive focus was no accident.

“We needed to address some needs defensively as far as sheer numbers,” Bobo said. “Quite frankly, we’ve had too much attrition on the defensive side of the ball the last couple years with guys we’ve signed that got here and didn’t make it for whatever reason.”

Of the position groups that CSU focused on in its 2018 class, none other may be more revamped than the defensive line.

The Rams signed six down linemen, more than a quarter of their total signees. The cast is split with three defensive ends and three tackles, a balance that Gilmore is pleased with.

“I think we’ve got some diversity in talents,” Gilmore said. “I think the class was very well thought out. There’s not a lot of duplication of the same guys, especially with the freshmen.”

Another position the Rams addressed is cornerback, as they will enter 2018 without three of their top four corners from a season ago. Bobo and company signed two athletic cornerbacks with length in Rashad Ajayi and Malcolm Magee, both standing 5 feet 11 inches or taller.

Just as important as the talent on the field, Lewis touted the defense’s mental approach in the opening weeks of becoming acquainted with the players.

“From a mentality standpoint too, it’s not just about talent or new coaches coming in that we’re going to change the world,” Lewis said. “The foundation’s there, we just need to tighten up some things and make a few adjustments.”

In addition to an entirely new staff, the defense will also feature new concepts. After the Rams played in 3-4 formation under former defensive coordinator Marty English, Jancek will implement a 4-3 scheme, adding an extra down lineman and playing three linebackers.

Despite employing a base 4-3 structure, Jancek reiterated that he wants to have the ability to play 3-4. He stressed the importance of considering each player’s strengths and weaknesses before forcing them into a system. After teaching everyone the same basics and rules, players can have the ability to develop their talents within the system.

“Some things that we’re going to immediately go to work at as soon as we get on the field is tackling and pursuing the football,” Jancek said. “Today’s game, it’s very challenging to play defense. If you don’t give great effort, if you’re not straining to the football and pursuing in the manner that you need to, it really can make things challenging.”

Though he originally intended to move spring practices earlier in the year, Bobo decided to keep things on a similar schedule as last year to give the many new hires enough time to prepare.

This year’s spring schedule is likely to mimic that of 2017, which began on March 21 and concluded on April 22. In the meantime, Bobo and the rest of the staff will continue their offseason efforts.

“(We hired) guys that I felt were going to fit us and fit that room defensively. I’m excited about all those guys. We’ve got experience, we’ve got youth, we’ve got guys with a lot of passion about being great.”

Collegian sports director Colin Barnard can be reached at sports@collegian.com or on Twitter @ColinBarnard_.