Jenson Button has dropped well off the pace of his McLaren team-mate Lewis Hamilton in recent races — so what's behind his struggles and can teamwork help him recover?
Button admitted that the Canadian Grand Prix was one of his worst races in recent years after he finished in 16th place, a lap adrift of winning team-mate Lewis Hamilton. The result continued a recent drop in form that has left him eighth in the title race, on little more than half the points collected by his title-leading team-mate.
After winning the season opener in Australia and finishing second in China in April, Button's form has tanked and he has scored just two points in the last four races.
As with all teams, McLaren operates the same base car and same parts (generally) but adapts the set-up to suit different driving styles — and this, they say, is where it has gone wrong for Button.
In a season when tyre degradation is so sensitive, minor modifications in car set-up can lead to major consequences.
The fluctuation in form of different teams has demonstrated just how hard it is to find the sweet spot for the tyres, and tiny tweaks can make such a difference in the grip generated by the tyres and consequent lap time — as big as 1.5s per lap in Button's case.
Button's smooth driving style, which is typically gentle on tyres, has left him struggling to get his tyres to working temperature and in exploring ways to do so each subtle change of set-up has taken his further away from Hamilton's.
In Canada, Button started on the soft tyres but had to pit before many of the cars on supersofts after suffering severe tyre degradation. While he insisted it is not a tyre issue, it is a tyre issue — but it's caused by the way the car has been set up, not the way he is driving.
The team had introduced a suspension set-up in Montreal that aimed to help Button 'switch on' his tyres but could it not be fully tested before the race due to a lack of running in Friday practice. In the race, it did switch the tyres on — but clearly too much.
McLaren said there was "nothing fundamentally wrong" with Button's set-up in Canada, but suggested they were subtle differences that combined to create such a big deficit between the two cars.
The problem is, tyres are so hard to predict they could be making the crucial tool for set-up development — the simulator — less reliable.
The lack of in-season testing and limited hours of Friday practice has made factory-based simulators of key importance. They can offer an indication into the base set-up for a track, but despite predictive models for tyre performance being available to plug into the simulators, it is very hard to get those models right and as a result virtually impossible to truly understand how the set-up will affect the handling and degradation through the course of a race — which is Button's biggest problem.
With the standard set-ups for Button and Hamilton apparently having deviated away from each other, the support between the two garages is very limited - so McLaren now appears to be looking to steer a more collaborative direction.
By pooling resources between the two garages in Valencia this weekend, they hope to get a more converged car set-up that performs well for both drivers.
This could provide significant benefit — as it effectively doubles the amount of time the team has to work towards set-up on the Friday — but it needs both sides of the garage to be happy to take a steer from each other's findings.
It's generally recognised that McLaren has the best car on the grid — but with only one driver on form, they risk throwing away the potential of a strong constructors' crown.
If Hamilton and his engineers can be convinced to help Button recover for the good of the team, then McLaren could rise to the top as the season heads towards a crucial point.