For most Premiership clubs with title aspirations it’s not the loss at Stamford Bridge or the Emirates that puts the trophy out of reach, when looking at the schedule those are games that a manager knows are hugely difficult to win. What separates winners from 3rd or 4th is the ability to win at the Stadium of Light, or at Molineux where the home team is compact, with men behind the ball unless they’re on the break. Often when his team is being kicked out of the game a manager might wish for an extra man in the final third, and they could have it if they thought out of the box a little and broke down their rigid four man backline. This tactic rarely works in places other than England, where there is still a lot of 4-4-2, with the two forwards easily corralled by the three center backs. In continental football, where 4-2-3-1 or 4-3-3 is often the case, the back three will be overran within the hour. However, in Premiership football this could be the difference between three points or one, and not just against the weaker teams.
Under normal circumstances, teams normally have a dedicated holding midfielder anyway, perhaps not an out and out tackler like Mascherano, but someone like Yaya Toure who could easily slip into a fullback position when needed and play higher up the pitch. It’s not impossible to switch to four at the back if in a position of dominance either. The key to the defense is having mobile defenders, because the wide center backs need to be comfortable tracking pacier wingers, while the middle could have the luxury of being a more aggressive type of defender. Full back runs would have to be tracked by the midfielders.
If a manager uses the extra midfielder or forward given to him with this shape wisely, the extra dimension brought to his team’s forward play makes them a real threat. Early on Roma used the shape to play another Dirk Kuyt-esque winger who tracked back but also ran forward giving them real width and numbers up the field. A side like Manchester City, whose fullbacks don’t really go forward that much (apparently Bridge did against Salzburg but I don’t think that’s the usual) and who play inverted wingers could really use this.
Of course this is an extremely situational performance, intended to cause the other team to play out of their comfort zone for a while. Some teams have solved their problems in other ways, Chelsea give Ashley Cole far more license than ever to bomb forward for example, but certain sides could really use this as another arrow in their quiver.