'The question is not when he's gonna stop, but who's gonna stop him.'
The quote is from the cult 1970s film Vanishing Point, but it could just as easily be about Sebastian Vettel's 2011 title campaign. While everyone has been very excited by all the overtaking in the first four races, Vettel has effectively led every lap apart from those last few in China. His other races have fallen into an identical pattern: win pole, lead away, get enough of a gap to allow him to respond to his pursuer's pitstop without losing the place, control the gap from there with enough in hand to keep himself out of DRS-trigger reach.
In that sense, his task has been relatively simple. Not easy - it takes huge focus and talent to consistently exploit even the fastest car - but straightforward in a way that his pursuers' races could never be. If only someone could get ahead of him at the start, prevent that RB7 from stretching its legs, imprison it behind a slower car.
That's clearly the way Jenson Button was thinking when he said of McLaren's prospects here in Spain: "Even if they qualify half a second in front of us, there's a long straight down to turn one. If you can get them into there, then the race is anyone's; it's no longer as straightforward as saying the quickest car wins."