The shape of things to come?

No formation is ever perfect.

After Napoli’s Champions League victory over Chelsea last week, there was much talk about the reemergence of the back three — and it has made a significant comeback in Serie A this season, with as many as 11 of the 20 sides employing the system on one weekend in January.

But Saturday’s 1-1 draw between AC Milan and Juventus showed the limitations of the system, or at least the limitations of Juventus’s application of it in this particular circumstance.