Driver profile: Jenson Button
Jenson Button got 2012 off to a flying start, with a win and a second place in the first three races, and at that point many were tipping him as the title favourite.
But then the wheels came off his campaign and Button scored just six points over the following five races up to Valencia.
There was a retirement in Bahrain as a result of car failure, but other than that the 2009 world champion has been utterly perplexed as to where his pace has gone, and so have his team.
It all seems a long way from 2011 when Button was the more impressive of the McLaren drivers - if not the out-and-out fastest.
Chief suspect for the source of Button's problems are the tyres - or, more specifically, the way he uses them. It seems he is simply not getting them into the correct operating window often enough.
Why it is happening to him more than Hamilton, and finding a solution to it, has flummoxed McLaren so far.
Whatever it is, a solution needs to be found quickly or Button's title hopes will be over before Formula 1's summer break.