The new rear wing system seems quite simple at first glance.
F1 rear wings consist of a large horizontal main plane section and a separate flap, which sits on the trailing edge of the main plane and is positioned at a steeper angle. The two work in combination to create downforce. In the new rules, at a given point a driver can alter the angle of the flap by moving the trailing edge down 50mm. This basically reduces downforce on the flap and in doing so also alters the airflow over the main plain, which reduces the downforce produced by that as well. The resultant reduction in drag means that the car's speed will increase to make overtaking a possibility.
But the way in which the system will be used is more complicated, and it is this that will determine its success or failure.
The system can be used at any time during practice and qualifying to enable teams to optimise their car's set-up when the system is in use - they must set the car's gearing to allow the top gear to handle the increase in speed when the system is operated otherwise the car would just hit the rev limiter and the system would be useless.
In the race, the system can only be used a maximum of once per lap and only in a predefined area along one specific straight chosen by the race director - basically the 200m or so before the braking area for the next corner at that part of the circuit. It is automatically shut off as soon as a driver begins to brake.
On the first two laps of the race or the first two laps after a safety car period, it cannot be used because at that point the cars would all be running too closely.
On top of that there are also some significant restrictions on whether a driver is allowed to use the system on each lap that are determined by the relative position of the cars around.
The system will only work when the chasing car is less than one second behind the car in front, and the car under attack will not be able to use the system unless it is within a second of another car in front of that. This will be continually calculated by the onboard ECU using timing data fed from the central timing and an indicator will show the driver if and when he can operate the system, which he will do by using a button.
The 'one second' usage rule is designed to give faster cars the additional speed needed to easily overtake backmarkers and midfield runners, but to ensure it is not too easy for cars that are similarly matched for pace to pass each other lap after lap.
The theory behind the system is good, but whether it will work in practice remains to be seen.