Daniel Ricciardo will have no greater chance to prove he is ready for the step up to Red Bull than his afternoon of running with the team at Silverstone on Wednesday.
He will be sat in the same car, and run at the same track, that Mark Webber scored a podium in a few weeks ago in the British Grand Prix.
There is rarely such a golden opportunity for back-to-back analysis of performance.
But even if he does a brilliant job in the RB9, Red Bull's chiefs are still going to have to do some number crunching to work out if the Australian is the man they need.
For Red Bull is not a team that can afford to be swayed by personal preference, a hunch, or a beaming Australian smile.
It is cold-hard statistics that will count for its verdict.
With the fight for the vacant Red Bull now appearing to have distilled down to a fight between Ricciardo and Kimi Raikkonen, Red Bull's ultimate decision boils down to not just which man it thinks is the fastest, but which man it thinks will bring home the points it needs.
A team's success in Formula 1 - both in sporting terms and commercially in terms of rights income - is wholly dependent on its finishing position in the constructors' championship.
While a team can rely on one superstar to do carry its hopes in the drivers' title chase, it needs another quick man alongside him to deliver the points needed for the teams' battle.
In each of the three constructors' titles that Red Bull has delivered since 2010, Webber's contribution was vital for it to take the team crown.
Last year Webber brought home 179 points; in 2011 it was 258 points, while the year before that it was 242.
AUTOSPORT has learned that Red Bull's analysis points to a target for its second driver of 200 points - something which it has no doubts that Raikkonen would deliver if he came on board.
The real issue now is whether or not Ricciardo can be relied upon to do the same.
That's not something that is going to be confirmed on the high-speed swoops of Silverstone this week.
But a swift integration to the car and team, and some positive signals behind the steering wheel, may be enough to show that the numbers can add up.