CPJ inherited a 7 win team and turned it into an 9 win team, which Chan was able to do just once in 6 years. Then the next year CPJ won an ACC Championship and 11 games, neither of Chan was able to do. Now that we will have a new coach next year (and I'm fully expecting it'll be a non-triple option coach), everyone is contemplating how bad the season might be or how long it might take to re-build. What conclusions can we draw from the state of affairs? Perhaps CPJ is a really good coach? Sure. Perhaps the CPJ's version of the triple option is a really good system? Of course. CPJ won with "someone else's" players and won with his own (e.g., 2014). Apparently, the new guy will only be able to win with "his" players.
Now that I've got that off my chest, I'll answer the OP's question. Provided that the new coach does a couple of things, the rebuilding period will hardly be noticeable. First, he must install an offense appropriate for the amount of time the players have. They don't have the time to learn a new playbook every week, so the new offense needs to have a standard set of plays that the players can rep every day and then each week the coach adds a couple of wrinkles to attack the opposing team's weakness. The offense does not have to be a system offense, but it needs consistency in it's approach - an identity, if you like. Second, the coach must install an offense that lets the players play in space. If he wants to line up in a classic I and blow people off the ball with a power run, the offense won't be successful. Think about the triple option, when the defense clogged the middle, either we ran rocket toss or pitched it on the triple - either way got the ball to a player with some room to maneuver. Third, keep the defensive staff intact. If the new coach tries to re-do both the offense and defense, it'll be too much - too many mental errors to overcome. Some coaches can turnover both schemes, but most coaches are not having to make such a drastic change on one side of the ball.
