There's rarely a golden bullet in Formula 1. Recent weeks have been dominated by talk of what might be the single factor that's helped Mercedes produce such a dominant car this season.
A fair amount of fuss has been made of the fact that the compressor on the Mercedes turbocharger is at the opposite end of the engine to the turbine. Could that be it?
There have also been suggestions that Mercedes hit the ground running because it has invested heavily in a state-of-the-art, full-car rig set-up at its Brackley base.