What is the impact of changing team's shape?

Football managers are usually to keep a team shape when it works. It doesn't happen ever. Sometimes, winning managers too are ready to change their team's pattern according to opponents' formation. They become more flexible when it comes to formations. Does it work? What is the impact of changing team's shape? It's in modern football an reasonable idea? Last week, Carlo Ancelotti took off Karim Benzema and lined up Gareth Bale as ‘false nine’. Daniel Carvajal started at right-back, while he utilized two centre-backs in Pepe, and Raphael Varane adding a third, Sergio Ramos, in the midfield. The selection of Ramos was a surprise: rather than playing as a right-back, he spent the game like an additional central midfielder. Acting in a central position in the holding role, he was involved in direct battles against Cesc Fabregas and Lionel Messi. That was Anceloitti’s idea. Ancelotti surprisingly omitted Benzema upfront but doesn’t employed Ronaldo into a centre-forward position. Instead he insert Bale into this spot. So we have Ronaldo spending most time on the left flank while Bale was interchanging his position with Di Maria while he was also trying to chase Sergio Busquets. This was an area of weakness for Real Madrid. Real suffered offensive problems with this pattern. While Ronaldo didn’t have his traditional partner in Benzema, Bale experienced a positional uncertainty. The result was that Real barely managed to construct offensively. But more interesting decision from Ancelotti was to employ Ramos as defensive anchor in front of the back four. Deploy a centre-back in the holding role is far from a news for Real Madrid, with Mourinho regularly lining up a defender in that role during a series of 2011 clashes against Barcelona. But the surprising move was that Ancelotti omitted the most obvious option, i.e. Pepe, deciding instead to utilize Ramos there. This wasn’t a successful move: Ramos wasn’t suited to play here and he also handicapped his game with an early booking and an overall troubled performances which convinced Ancelotti to take him off. Ramos wasn’t brilliant as passer - and he clearly couldn’t - but he was supposed almost to be able protecting the centre-backs. Instead, he didn’t and the movement of Messi and Fabregas was effective. Another example came from Manuel Pellegrini during last game between Manchester City and Chelsea. It was a match between two contrasting style. Manchester City likes to play a ball retention game while Mourinho's side is devastating playing counterattack. To face Chelsea’s offensive trio of Eden Hazard, Oscar and André Schürrle, Chilean manager Pellegrini made the decision to change his pattern switching away from his classic 4-4-2 to add an extra man in the middle of the pitch utilizing three central midfielders. With Fernandinho playing as central midfielder, Pellegrini moved up Yaya Touré in an attacking midfielder spot, inserting Javi García as a holding midfielder. This was a line-up selected to retain the ball control but also to prevent Chelsea from playing through breaks. The difference between it and a classic Pellegrini’s side was high when you think he never fielded Javi Garcia, Fernandinho and Toure together. It was the right move? Although the Fernandinho-Toure duo looked weak against counter-attacks, as neither is a natural holding midfielder, this was a big move away from Pellegrini’s classic 4-4-2. Team seemed not comfortable changing its shape. There remain significant questions about how and when change a team’s standard formation to employ a different approach. Changing a formation considering opponent’s strengths probably made sense overall but there are clear problems and counterindications. For example, a manager take the risk to send his players a message of weakness not insisting upon his team’s classic approach. Any change may come as an instability factor. Adapting to rivals by changing the shape still can produce but can also risk to generate confusion on my own team.