For coach Deion Sanders and the Colorado Buffaloes to make a significant improvement, being able to hold up against top-tier Big 12 competition is critical, especially with what looks to be a tough conference schedule next season.To make that improvement, Sanders and the Buffaloes have made several changes to the roster and the coaching staff, which includes new defensive coordinator Chris Marve, who has experienced previous success as a defensive playclaler namely during his time at Virginia Tech from 2022 to 2024.With Marve now calling the defense, Colorado could be in a prime position to take a major step forward and compete at a much higher level in the Big 12. CU football head coach Deion Sanders, or Coach Prime, watches his team warm up before the game against CSU in the Rocky Mountain Showdown at Canvas Stadium on Saturday, Sept. 14, 2024, in Fort Collins, Colo. | Cris Tiller/For the Coloradoan / USA TODAY NETWORK via Imagn ImagesStopping The RunThere is no question that the Buffaloes’ biggest weakness in 2025 was the ability to stop the run as Colorado allowed 222.5 rush yard per game and ranked as the 135th defense against the run in the entire country.With a poor rush defense, the Buffaloes were unable to consistently get stops because opposing offenses were able to run the ball successfully and were constantly in manageable situations on third and fourth downs.When offenses were constantly in manageable situations, it became very difficult to get stops for Colorado, and also significantly shortened the game, which limited the Buffaloes' opportunities on offense and was part of the reason that Coach Prime and Colorado finished 3-9.MSU defensive run game coordinator Chris Marve speaks to reporters at Media Day on Saturday, August 10, 2019 at the Leo Seal Complex. Photo by Keith Warren