Before the first-lap controversy and dramatic race that followed, the fallout from McLaren's split with Honda -- and the various other deals that move triggered -- dominated much of the Singapore Grand Prix build-up. The new deals made have not only shaped the 2018 grid but changed what the next few seasons of Formula One and beyond could look like. Here, ESPN looks at each aspect of the deal and who seems to have been on the best and worst ends of it.
At face value, ditching Honda is a sensible decision for McLaren. This is its third season languishing well off the pace with a manufacturer that came into Formula One making big promises but has since spent most of its time missing its own targets. This year the relationship reached breaking point, with the situation complicated by star driver Fernando Alonso also discovering the limits of his patience as soon as Honda's dire situation became clear to McLaren in winter testing. The team has called the partnership a "proper disaster" in terms of its credibility and to its hopes of securing a new title sponsor, something CEO Zak Brown promised would be found by 2018 when he took the job last year.
Put simply, the McLaren-Honda era so far has been a painful embarrassment for both those inside the team and those on the outside looking in. Moving to Renault promises better results next year with a more competitive engine, one that Red Bull has used to stay best of the rest behind Mercedes and Ferrari and occasionally challenge for wins at circuits where it can flaunt on the strength of its chassis -- an area McLaren has repeatedly boasted about during its struggles with Honda.
The most obvious silver lining to the deal is that it almost certainly means Alonso will still be in McLaren colours next year. The Spaniard has consistently made clear that his problem has not been with McLaren and, though he denied making the team an ultimatum between keeping Honda or himself, it's difficult to imagine he would have stomached another season with the Japanese manufacturer.
Verdict: Getting shot of Honda engines for 2018 seems to be a win-win until you start pulling at some of the threads of this complicated tapestry. The first, and most serious question, is whether McLaren has put its long-term future at risk to ensure short-term results.
So far former team boss Ron Dennis has been proved right in his prediction that the current regulations make it impossible for a customer team to win a championship -- the reason he sought out Honda in the first place. Honda has suggested McLaren did not adapt well enough to the factory partnership to make it work and Red Bull's failure to compete for a championship in the V6 turbo era as a Renault customer supports the argument the new deal is a far from perfect solution for the Woking team.
McLaren has, in essence, swapped the long-term stability of a factory deal -- however painful it might have been so far -- for the short-term gains of a more competitive engine, one which has still failed to solve the worst of its reliability problems in 2017. When the current regulations end McLaren has at least given itself flexibility in choosing what powers its cars post-2020 -- though this itself is no guarantee of success; the team faces the prospect of building its own engines or trying to lure another manufacturer into the sport to start from scratch, as it did with Honda in 2015. NS
Although Red Bull's engine situation will remain unchanged in 2018, the team had a significant interest in the weekend's deals -- not to mention the ability to make or break the whole chain of events. Contractually, Red Bull owned two of the three Renault engine supplies for 2018 and it could have blocked a McLaren-Renault alliance by insisting Toro Rosso stay with the French manufacturer next year. That would have ensured McLaren -- one of Red Bull's natural rivals in F1 -- stayed with Honda for another year, while also continuing to benefit from the cost-saving component sharing it currently enjoys with Toro Rosso. By allowing the deal to go ahead, Red Bull has potentially allowed McLaren to become a direct challenger for the podiums and wins it will be targeting next year, while its junior team will be stuck with what, up until now, has been the least competitive engine in F1.
But for Red Bull, the Toro Rosso deal was not about 2018. Both senior and junior team only had one year remaining on their Renault contracts and it was looking increasingly likely that the French manufacturer would ditch both teams in 2019. By switching Toro Rosso a year early, Red Bull will gain a much better understanding of what is needed to make the Honda a winning engine in 2019 should it also need to switch to Japanese power a year down the line.
Carlos Sainz has left Toro Rosso "on loan" to Renault, suggesting he could come back in 2019 should either Daniel Ricciardo or Max Verstappen make a move elsewhere. It also allows Red Bull to promote its junior driver Pierre Gasly to an F1 seat after the GP2 champion spent a season in Japan's Super Formula this year.
Verdict: Whereas Toro Rosso was once just a finishing school for Red Bull's young driving talent, it is now also an engineering test bed for the senior team. At first it seemed like Red Bull would have a choice between Renault and Honda in 2019, but it now looks increasingly likely that the French manufacturer will make that decision for it.
If that's the case, then it's better for Red Bull to have some first-hand of experience of what it will be like working with the Japanese manufacturer via its junior team than go into 2019 completely blind. LE
On the face of it, Toro Rosso will lose out in 2018. It will have the least desirable engine package in Formula One and it will also lose star driver Carlos Sainz to current rivals Renault. But where there is short-term pain there is often long-term gain, and for the first time in its history it will become a works team.
Honda essentially started from scratch this year and its latest power unit has a much lower centre of gravity as well as a similar architecture to the class-leading Mercedes. If Honda can make progress with that concept over the winter, it will give Toro Rosso the basis of a very competitive package and, what's more, it will be able to integrate chassis and engine as only a works team can. Honda is convinced Toro Rosso will be easier to work with than McLaren, and the combination of greater flexibility from the chassis side as well as less media pressure overall could be the perfect environment for the Japanese manufacturer to flourish.
Verdict: Toro Rosso faces a lot of early pain as it adapts its 2018 plans to accommodate a potentially underpowered and unreliable Honda power unit, but long-term the deal should provide a bright future for the team.
Following the graduation of Daniel Ricciardo, Max Verstappen and Carlos Sainz from the team, Red Bull's pool of young talent appears to be drying up. That makes the cost of running a junior increasingly hard to justify for Red Bull, but as an engine test bed Toro Rosso now serves a secondary purpose. If all goes well, Honda will improve over the winter and Toro Rosso will enjoy a season with exclusive access to the Japanese technology before again sharing its drivetrain with Red Bull in 2019.
If things go badly Red Bull may start to question its own future in the sport, but Honda -- seemingly determined to see its F1 project through -- could consider Toro Rosso as the most obvious route to setting up a works team. Either way, Toro Rosso's long-term prospects seem better with Honda than without. LE
Honda's three years with McLaren have been disastrous for the manufacturer's image. Struggling in 2015 was forgivable given the complexities of the regulations it entered into, but its repeated failures, continual insistence a major turnaround was on the horizon and broken promises was not. But progress was being made in 2017. Recent upgrades -- though rarely arriving on time -- gave clear gains to McLaren, though nothing close to enough to make a serious step towards Mercedes or Ferrari but enough to suggest Honda has got its head around the most fundamental flaws of its current engine.
By switching to Toro Rosso, the Japanese company moves itself out of the limelight it has wilted under since partnering with McLaren. Honda might not have helped itself by immediately targeting third with its new partner, which has scored just one win in its time in Formula One, but will face lower expectations internally from Toro Rosso than it did at McLaren. As mentioned above, Toro Rosso gives Honda the option of making the Faenza squad its own factory outfit or a pathway to linking up with Red Bull in 2019, a partnership which could challenge for a title if it involves the competitive engine the former world champions have craved since 2014.
Verdict: Honda deserves credit for not cutting its losses and quitting Formula One when it became clear McLaren was seeking an end to its partnership. Though it would have prevented further embarrassment, walking away would have also prevented Honda from proving it can still win in Formula One -- something the last three seasons will have caused even its most ardent fans to doubt.
Honda is a proud company clearly hurting badly from the failure of its partnership with McLaren. For all of its heritage, the newest generations of F1 fans will only know Honda for its difficult spell in the mid-2000s and now its failure to give McLaren -- and, primarily, Fernando Alonso -- the car to even challenge for a podium for three years in a row.
The path back to glory might look even longer without McLaren but Honda knows reaching the top of the sport again is essential if it wants to wash away the damage done to its image since 2015. NS
While it continues to work towards a target of fighting for championships with its works team in 2020, Renault is happy to have competitive engine customers to battle against and receive feedback from. The French manufacturer continues to run its customer engine programme as a business and in McLaren it has a very keen customer.
It was noted in the announcement that the McLaren deal comes with "marketing and communication benefits", presumably in terms of exposure of the Renault brand on a level that Toro Rosso simply can't offer. The McLaren partnership also comes with none of the baggage that the Red Bull relationship suffers from, and it is looking increasingly likely that Renault will cut its ties with energy drinks company in 2019.
It will also gain Carlos Sainz on a one-year loan deal from the Red Bull family, ensuring a formidable partnership of Sainz and Nico Hulkenberg next year. Renault targeted the Spaniard as a potential race driver for this year, but Red Bull spiked the deal before it could get off the ground. Renault will be keen to convince Sainz of the benefits of driving for a works team long-term and it could be the platform for the Spaniard to sign a long-term deal with the French team.
Verdict: Renault needs customers for its engine programme, so it may as well have willing ones that are keen to support Viry-Chatillon's efforts rather than criticise them. Securing a deal with McLaren for the next three years means it can cut its ties with Red Bull in 2019 if it wants, while also building up the competitiveness of its works team at the same time. What's more, if it returns Fernando Alonso to winning ways, it can take some of the credit for what would be a great news story.
The obvious downside is that it could end up being the slowest of the three Renault-powered teams next year, but based on the current constructors' standings that wouldn't be a major change from the current situation. Securing Sainz represents a big bonus on top. LE
Just a few months ago, Carlos Sainz cut an agitated figure. His exciting career appeared to have come up against a brick wall, with his only contractually possible step up the grid blocked by Red Bull's Daniel Ricciardo and Max Verstappen and a watertight contract making escape from Toro Rosso impossible. He even came into conflict with Red Bull's senior management during the Austrian Grand Prix after suggesting he would not be at Toro Rosso for a fourth season, which led to a slap on the wrist and a warning not to "bite the hand that feeds you" from Helmut Marko.
Another season at Toro Rosso would have been an uninspiring prospect for Sainz, given the team's failure to move up the pecking order in recent seasons. In moving to Renault, he will partner Nico Hulkenberg, who is likely to provide more of a challenge than current teammate Daniil Kvyat. As this year's results prove, Renault is a team on the up and Sainz's prospects in yellow are much better than he could have hoped for had he stayed put for another season.
Verdict: At present, Sainz looks like the undoubted winner from the whole deal. Each other part of it carries an 'if' and a 'maybe', but for Sainz the move breaks him free of a situation which could have hurt his prospects beyond 2018. As with any move, there's the chance he could struggle to match a more experienced teammate in Hulkenberg, but regardless of how it pans out it's an opportunity which would not have existed without this deal coming together in the way it did.
Sainz is an immense talent and at Renault he can both prove his worth to Red Bull in case it loses either driver in 2019, while simultaneously showing the rest of the grid the talent at his disposal in case Max Verstappen and Daniel Ricciardo stay put. Red Bull's loss would be another team's gain -- wherever Sainz ends up in 2019, it's hard to see his career taking a backwards step if he delivers for Renault next season, it's just hard to predict exactly which car he will be driving. NS