saying it is the biggest weakness of the team is simply wrong.
The defensive performance, specifically the complete ineffectiveness of the ability to bring a runner to the ground, allows every team on the schedule to compete with and beat ND. It is comically bad, or at least has been consistently. Solve that and this team can win 6 or 7 games. But, to win 'em all, they do need the threat of a power run game utilizing a fullback. It opens up so many options that opponents do not pay any attention to in the red zone currently. Developing sets and personnel to use in the red zone should be a priority at some time for Kelly....but after 7 seasons at ND, the hope of that ever happening is dwindling and approaching zero. IMHO, it is one of a few major flaws in Kelly's approach to the game. (Notice I did not say it was THE flaw....:)