It's hard for me to credit Digger Phelps for anything (just kidding, Digger), but in this case I have to. He taught me how to be a head coach. Well, actually he taught Danny Nee how to be a head coach and, when Danny Nee hired me at Ohio University, he started the process of training me.
Drawing from his time as an assistant coach at Notre Dame, Nee entrusted me with responsibilities that included coaching on the floor, recruiting, breaking down film and scouting, developing and giving academic support to our players, running the summer camp and speaking on behalf of the basketball program in public. He was clear that this was how he learned from Digger. In fact, guys like Tom Izzo, Roy Williams, John Calipari, Kevin Stallings, Jim Larranaga and Rick Barnes started the same way I did. I know because I ran into them all the time on the road recruiting and scouting opponents. And, while they all were excellent recruiters, they were more than that.
The trend in recent years has been to hire assistant coaches primarily for their recruiting prowess. And, while procuring players is a key to any coach's success, the job carries way more responsibilities than that.
At the risk of sounding "old school," I don't think young coaches put the time in to learn the game the way that they should. I laugh when I hear someone described as a "skill-development coach." We used to call that guy an "assistant coach." There was no specialization. How could you grow as a coach if you were only good in one area?