The cars aren't the stars at the first F1 test

The cars are usually the focus of attention at the first test of the Formula 1 pre-season, doubly so since the winter programme was homogonised with scheduled group tests in 2010.

But every now and again, we are lucky enough to have the chance not only to admire the new machinery, but also to have a glimpse of something else very fresh.

This year, it will be the sight of Sebastian Vettel in Ferrari kit and the not-so-new, but still remarkable to anyone who remembers 2007, view of Fernando Alonso back in McLaren colours.

Changes among the big teams always generate extra excitement, and with Daniil Kvyat promoted to Red Bull's A-team, three seats in the top four teams have changed hands.

Some F1 test crowds would make struggling grands prix envious © LAT

Probably the most memorable pre-season test of this era came back in 2010. Massive crowds flocked to Valencia (the road course, rather than the terrible street circuit) to see Alonso on his first proper outing for Ferrari.

There were huge traffic jams and crowds that would put some grand prix Sundays to shame. And most were there to see their beloved Alonso take his first step on the path to a string of titles with Ferrari.

Well, they weren't to know...

But that year it wasn't just Alonso. There was also reigning champion Jenson Button switching to McLaren, and Michael Schumacher back in F1 at Mercedes alongside former Williams driver Nico Rosberg.

Then there was Rubens Barrichello moving to Williams and Robert Kubica in new surroundings at Renault. It's a cliche, but it really was a case of 'all change'.

This gave the F1 grid a fresher look than even a whole field of new cars could. And in these days of drivers generally spending longer in the employ of one team - certainly the most successful ones at least - it's something that doesn't happen often enough.

Arguably, before 2010 the last time there was a switch-around on such a grand scale was in 1996. Six of the eight drivers in the top four teams from the previous season moved, and while Damon Hill (Williams) and Mika Hakkinen (McLaren) sat tight, there was chaos around them.

There was lots of movement in the driver market for 1996 © LAT

Again, Schumacher was at the centre of this, moving to Ferrari with Eddie Irvine. Then there were the old Ferrari boys, Gerhard Berger and Jean Alesi, heading to Benetton, Jacques Villeneuve in at Williams from CART Indycar and David Coulthard joining McLaren.

These were great storylines in a sport that, for all its mechanical machinations, is still as much about the flesh-and-blood in the cockpit as anything else.

Looking back to this year, it will be intriguing to see how Vettel fares at Ferrari compared to struggling Kimi Raikkonen. As for Alonso, can he assert himself in a McLaren team that once shunned him, while going up against a team-mate (Button) who is part of the furniture at Woking?

The reason these questions are so intriguing is that it's so rare to get direct comparisons between drivers in such a car-dependent sport.

While there is similar excitement in team sports such as football, where a big-name player can switch clubs and generate massive interest, such changes are uniquely powerful in F1.

Success in football, in terms of honours won, is clearly team dependent. But even in a squad of donkeys, a truly extraordinary player can shine.

But there is always the suspicion in motorsport that the car is contributing more than the driver. It's not an unreasonable position, for it's a combination of the car (and all its components, including the tyres) and the laws of physics that dictate the ultimate performance potential.

Champions with a lot to prove - Raikkonen and Vettel - are now team-mates © XPB

That said, approach it from another angle, and the driver is essential because they are the one capable of extracting 100 per cent of that potential. But where exactly does that potential lie?

Alonso seems an open and shut case. On Sunday afternoons, he is a formidable performer. Unless he's in one of his occasional strange moods, when he can't seem to push himself to operate at the limit, he rarely extracts anything less than the maximum from the car.

He will do so again at McLaren. The more interesting question there is where the Honda-powered machine's potential runs out, and what might happen if it doesn't approach the level needed for race wins.

But Vettel is an even more interesting case. His 2014 season was mediocre. Not as bad as some make out, but he was not operating at anything like the level he did previously and never seemed to buy into the demands of last year's Red Bull.

Failure to adapt to the driving style required of the post-exhaust blown downforce cars was at the heart of this problem. That error was Vettel's, no one else's, for it is the driver's job to adapt to the demands of the car.

Yes, you can change the car to an extent, pursue certain characteristics, but the best drivers are versatile. They have to be.

Alonso will be trying a new McLaren again, eight years on © XPB

This year, Vettel has to show that 2014 was an off-year, the consequence of four years of overachieving combined with coming back down to earth in a car that wasn't capable of winning the title.

Based on the evidence so far, last season was an outlier, perhaps caused more by his own inability to focus to the same level. Adapting has not been a problem before as he has won in a wide variety of machinery.

And still, the extraordinary way he mastered the counter-intuitive technique required to get the most out of exhaust blowing is not widely recognised.

But he cannot afford a second year like that. This is what he must avoid, and to do that he needs to beat Raikkonen emphatically. If he doesn't, his stock will have lost value, perhaps forever.

It's likely that Vettel will deliver. There are indications that the change of scenery has not come a moment too soon and the new challenge will allow him to regain that ferocious attention to detail and desperation to succeed that wasn't always in evidence last year.

This is why top drivers changing teams is always so fascinating. There is an endless appetite to understand these extraordinary athletes and their capabilities, so to see them in different surroundings cannot fail to be gripping.

That's why, once the initial excitement about fractionally-less-ugly-but-still-ugly noses has faded, it will be those in the cockpit that hold the attention of the watching world.

And rightly so. The machines are a big part of the appeal of motorsport, but to the majority of those watching, the drivers are the beating heart of the grand prix car.