Coach Jim Harbaugh, whose helmet was stuffed with Wolverines decals as a star quarterback in the 1980s, brought back the tradition when he returned to headline the program in 2015. As Michigan neared 1,000 all-time wins, Harbaugh changed philosophy in 2021, opting for a team-based model that included the all-time win tally on the victory stickers.
“The way the sticker was didn’t really tell you anything. There was only one sticker,” Harbaugh said. “But then the boys could know for the rest of their lives what that sticker was for and what it meant.”
https://www.espn.com/espn/feature/story/_/id/34839671/how-helmet-decals-tell-story-michigan-ohio-state How helmet decals tell the story of Michigan and Ohio State