I've read that the really old bucks don't even participate in the rut much. Oftentimes they will have few if any scars from sparring. They don't chase many does and do not breed often. I guess they're so old and experienced that they've decided that staying alive is more important than sex. These bucks may only be seen once a year and rarely even show up in trailcam photos. Can't remember where I read this,but it makes sense.