The availability and quality of personnel determines a system or a formation. It is usually a fan’s concern to ponder on what the system of play is or was at any given time.
Usually the concerns are misplaced as the understanding is usually wrong. The questioning the fan wants to know the answer to is, who was playing. The distribution of personnel on the field of play is very vital in determining a system. It is easier for anybody to understand this.
Tactically speaking, it is rather the functions of these people who are distributed on the field of play. A player will usually play one position in general and then be asked to perform a certain role in particular in a certain match.
Team tactics, after considering the material at hand, will dictate what roles are the players going to be engaged in. Playing Cesc Fabregas, Wayne Rooney, Fernando Torres and Didier Drogba in a team with a goalkeeper and 6 defenders does not necessarily mean you are playing a 1-6-1-3 formation.
In the above scenario, the intentions may be that Torres plays a lone striker role, Rooney and Drogba playing a supporting role from midfield. Two of the 6 defenders will be winning balls in midfield but retracting to defensive positions when possession is lost.
Teams prefer to utilise a single conventional striker these days, ie known individuals like say Asamoah Gyan. He endeavours to stay with the last defender and both flanks on his right and left are void of anyone. This creates space for him to run into, or in the case of Brazil, for Robinho and Fabiano to exploit when Kaka or Lucio surges forward with the ball.
Systems and formations will manifest better when the team is not in possession of the ball. At this moment you see the shape and behaviour that will tell you the system. Romario used to be exempt from any defensive duties at all for both Brazil and the teams he played for.
The great Marco van Bastern was known to defend and attack in one swift movement. In these days of having a packed midfield it is not necessary, but it depends entirely on the coach.
People always want to know which systems rocks. None, It is only a question of philosophy of the coach. Coaches do the football according to their selfish taste. Strong coaches will create systems in a stubborn manner to yield the results they want. In other words they prefer to create problems for others. The other part prefers to solve these problems.
Some of the rigid type of coaches will play the same formation day in day out. They will usually force system they believe in on the players. The other part will depend on the teams they play and are adaptive within certain parameters.
Team chemistry, personal relationships, team maturity level and type of competition are some of the things that will determine the type of system to be implemented.
What is your observation of South Africa 2010 FIFA World Cup systems and formations or your take on the subject in general?