Jenson Button signed a contract with Williams ahead of the 2005 season, but BAR Honda still had an option on him and took the case to court. Ultimately, the CRB ruled in BAR’s favour and Button had to stay.
What if BAR did not contend the contract, and Button was allowed to re-join his former team Williams, as he actually wanted at the time?
2005 season
Button would join Mark Webber at Williams-BMW, but who would take his position at BAR next to Takuma Sato?
Their best options would have been to sign one of the experienced drivers such as David Coulthard, Nick Heidfeld, or to bring back Jacques Villeneuve who previously drove for the team for years. Promoting test driver Anthony Davidson was another option. Ultimately, Heidfeld was probably the best option at the time, and it’s easier for our What-If to simply imagine a switch between Button and Heidfeld for the 2005 season.
Lineups:
Williams-BMW: Button – Webber
BAR-Honda: Heidfeld – Sato
In terms of performance, Button most certainly would have beaten Webber over the 2005 season, but the Williams wasn’t a top car. Webber scored 36 points; our simulator shows Button would have scored 48, with 4 podiums and 1 pole position. He would have advanced to 6th place in the standings, better than his original 8th.
Over at BAR Honda, Heidfeld would have out-performed Sato but scored fewer points than Button did in real life. He likely would have managed 22 points, a downgrade to 12th in the standings, but based on a huge advantage over Sato who had a horrible season, Heidfeld’s reputation would actually improve.
2006 season
Button and Webber would both have stayed at Williams. Engine supplier BMW would still choose to buy Sauber though, leaving Williams with a weak Cosworth engine.
With Heidfeld now under contract at Honda, and BMW taking over Sauber, the latter would not be able to sign Heidfeld as in real life. They would still have Jacques Villeneuve to start the year. Who would be the second driver? The obvious selection is that Robert Kubica would be placed in the car earlier. But! Remember that Nico Rosberg cannot debut for Williams as both seats are taken. He would almost certainly join BMW-Sauber in this alternate scenario, as he is now the best young driver available. Rosberg tested for Williams-BMW in 2005, so moving with the German manufacturer to BMW makes sense if there isn’t a slot open at Williams.
Lineups:
Williams-Cosworth: Button – Webber
Honda: Heidfeld – Barrichello
BMW-Sauber: Villeneuve – Rosberg
Button would struggle all year at Williams. His advantage to Webber would be smaller than the year before – the two drivers may even perform at the same level, as Button has a history of caring less when driving a backmarker car. In any case, Button has an unnoteworthy year and doesn’t score too many points.
Heidfeld was at his peak in 2006. Him and Barrichello would probably perform similarly, as Barrichello – an otherwise better driver – struggled a bit in his first year at Honda.
Rosberg would beat Villeneuve as a rookie, giving him an excellent reputation from the get-go.
Nothing changes at the front of the field. Yet!
2007 season
Button stays at Williams, while Webber moves to Red Bull as in real life. Williams’ uninspired signing of Alex Wurz is also repeated here, sadly, as Sebastian Vettel would have been an option.
Honda keeps its lineup from the previous year. At BMW-Sauber, Rosberg is now already the lead driver, joined by fellow youngster Robert Kubica.
Lineups:
Williams-Toyota: Button – Wurz
Honda: Heidfeld – Barrichello
BMW-Sauber: Rosberg – Kubica
Honda had a terrible car in 2007 while the Williams was just okay. Button easily beats Wurz, while peak-Heidfeld beats a well-performing Barrichello, yet without many points to show for it.
Rosberg would have been ‘best of the rest’ after the unbeatable Ferrari and McLaren cars of 2007, similar to how Heidfeld’s season went in real life.
2008 season
In the real world, Button suffered under several slow Honda cars during these years but stayed. So we assume he would do the same at Williams and stay with the team despite lack of results. He is paired with Nakajima for 2008, an easy matchup.
Honda maintain their lineup yet again, and BMW-Sauber does the same. So the changes around the paddock are still fairly limited compared to other What Ifs.
Lineups:
Williams-Toyota: Button – Nakajima
Honda: Heidfeld – Barrichello
BMW-Sauber: Rosberg – Kubica
Button obviously destroys Nakajima and performs better than Rosberg did in real life. He finishes just 11th in the standings, though.
Honda also have a terrible campaign, not achieving much, as they are building their 2009 car which they will still abandon.
BMW have more success; Rosberg has a few highs and even manages a win, but it isn’t enough to truly compete for the title. An emerging Kubica performs almost at Rosberg’s level, just slightly slower than the German, and still wins in Canada.
2009 season
Now it gets interesting! Button stays at Williams as several manufacturers plan to leave the sport. He is paired with Nakajima again for an easy beating.
Ross Brawn still takes over Honda, this time with Heidfeld as the driver next to Rubens Barrichello.
BMW-Sauber retain their young but seriously talented lineup.
In other words, no changes from 2008 except Honda becoming Brawn.
Lineups:
Williams-Toyota: Button – Nakajima
Brawn: Heidfeld – Barrichello
BMW-Sauber: Rosberg – Kubica
Sadly, Heidfeld is not quite able to emulate Button’s 2009 performance. Barrichello gets closer than he did in real life, even beating Heidfeld to secure second place in the championship. But ultimately, both Brawn drivers are defeated by Sebastian Vettel who has an easier way to the title.
Button performs admirably at Williams, but it just isn’t enough. He finishes 7th in the standings just like Rosberg did.
For BMW, it’s a lousy season, as the team prepares to leave the sport. The drivers don’t care though, as they are easy targets for other strong teams.
2010 and onwards
From here, we can continue to speculate.
Does Button stay true to Williams, or does he move to McLaren as in real life?
His reputation is now absolutely set in stone as a standout midfield performer, and not as a world champion. He is most likely winless up until this point.
If he stays at Williams, his career will be continued to be defined as such, and if he goes to McLaren, we can except similar results as he actually achieved in the 2010-2016 MP4’s; perhaps with less confidence, but more hungry for wins.
Summary
In short, it likely would have been disastrous for Button to sign with Williams, and he should be forever grateful to have stayed with BAR/Honda/Brawn as it ultimately earned him a Grand Prix win in 2006 and a championship in 2009.
Aside from 2009, Button’s change to Williams doesn’t change too many things around the paddock. But it would have been interesting to see different drivers in different teams.
Vettel (now the 2009 champion), Heidfeld (race winner for Brawn), Barrichello (an easier team mate at Honda/Brawn) and Rosberg (debuting for BMW rather than Wiliams) may all have benefited from it. But for everybody else, things mostly remain the same.