The "perfect storm" that triggered Williams's leap

If Racing Point or Toro Rosso had fought for pole position in the Hungarian Grand Prix it would have been an almighty surprise. They would have required an unthinkable leap of between 1.5-2% in lap time from one weekend to the next to trouble Mercedes and Red Bull.

Such performance gains are difficult to find over an entire season, let alone a few days. So no, neither found 2% in lap time and pumped in a pole lap in Hungary. But Williams did...sort of.

A "perfect storm" facilitated George Russell's 16th place start for the final race before the summer break, unspectacular in isolation but stunning in the context of a Williams team cut adrift at the back of the field all season and regularly qualifying with the two slowest cars.

So when Russell produced his magic lap, beating both Racing Point cars, an Alfa Romeo and a Renault, he said afterwards: "It really felt like a pole lap for us."

This was an enormous step for Williams in a season that started in a frenzy of setbacks: car late to testing, car slow at testing, car's technical director Paddy Lowe leaving, car requiring design tweaks to be legal for the season opener in Australia.

It took time, but in Britain and Germany, Williams's efforts behind-the-scenes - a full story in its own right and one to be documented by Autosport in the coming weeks - bore fruit in the form of significant upgrades: turning vanes, bargeboards and floor among the areas given a radical facelift.

The reason Hungary was still a big surprise is there had been no major step in Germany. Williams's fastest lap of the weekend, its 'supertime', was 104.116%. That was lower than its seasonal average but actually worse than it had performed in Britain, and still represented a bigger gap to the next team (2.2%) than that team, Toro Rosso, had to pole position.

But then things changed. Russell's effort meant Williams's supertime was at 103.297% off the ultimate pace, set by Max Verstappen's Red Bull. Still not quite to the proximity to pole as it was at Silverstone, but much more significantly it was the first time it was not the slowest at a grand prix, outpacing Racing Point, and it put the team firmly part of the scrap in the tail end of the midfield.

"At the moment I would say it was a bit of a perfect storm," says senior race engineer Dave Robson. "We'll review in Spa on Saturday evening and see whether we've actually made a significant step forward - and whether we can adapt what we've learned here to suit Spa."

This suggests that Russell has something Kubica does not. But this does not mean a more favourable car. Perhaps the man in the cockpit is making the difference

This medley of factors includes tyre performance, the Hungaroring's layout, the aforementioned updates, Russell's own individual quality and a sprinkle of fortune.

Russell would probably not have been in Q2 contention had Sergio Perez and Daniel Ricciardo not conspired to massively compromise each other starting their final flying laps. So that presented an opportunity, one that Russell so nearly took.

And he played a key role. His execution of the lap was almost flawless, barring a minor twitch through the final corner as he started the flier, a tiny mistake that cost him a tenth by the time he was at Turn 1 (and he missed out on Q2 by half a tenth). But it was also part of what Williams thinks might be a vital breakthrough.

"Sector two, fair play to George - he was outstanding through there," says Robson. "The speed he carried through some of those corners was extremely good.

"It's a pretty technical circuits and the last three corners you've got to get the line right, and a line that's sympathetic to the tyre state you arrive at those corners with. In some way, what you can do there is set by what you did two miles earlier."

This relates to something the likes of Ferrari and Haas have been keen to document, that tyres are a massively shifting variable in 2019. Williams, Russell revealed over the weekend, thought it was on top of this. But it has been convinced otherwise.

"We felt prior to this weekend we didn't have the tyres in a perfect window, so we decided to take a different approach, try some different things," says Russell.

"These tyres are just a very tricky thing and when you get them working, you're battling with a completely different beast. We've been less vocal about it because we thought we were making the most of it, but this weekend has proven that we were not."

This is why Russell was so positive after Friday practice, while others maligned the lost track time in the rain-hit second session. In the dry and in the wet, Russell felt his car transformed from the previous weekend. And he put it down to tyre prep.

"I was trying very drastic things with my warm-up procedures to try and get different ends of the spectrum, and sort of found the midpoint where I found where the best compromise was," he says.

"You've just got to be dynamic to a situation and we didn't fluke into it, we came into Friday with a plan to try different things and to try and do a better job with the tyres. It has been a more satisfying performance from that perspective, going into this weekend purely focused on that and actually achieving it is a really great feeling."

If this was purely a Williams breakthrough, we could expect Robert Kubica to have followed Russell's lead in claiming a few midfield scalps. Instead Kubica slotted into his now-normal 20th place in qualifying, 1.3s slower than his team-mate.

As Kubica put it: "There's no rollbar or ride-height change that can give you one second. It's a question of putting things together."

This suggests that Russell has something Kubica does not. But this does not mean a more favourable car. Perhaps the man in the cockpit is making the difference - not in terms of being 1.3s faster than Kubica, for even a Kubica whose powers have waned is not that slow. But grip and confidence is a powerful combination, one that could very quickly add up to 1.3s around a full lap and one that can be entirely influenced by tyre performance.

Williams is optimistic for Russell. Even though it will head to the Belgian Grand Prix and slip further back, particularly as another factor that likely contributed to its strongest showing of the season is - as Robson suspects - the Hungaroring suited its car quite well.

The question for the team now is whether Hungary was a fluke or a turning point

Should this happen, Williams will hope to at least be on the fringes of the midfield fight and not back in no-man's land. And if nothing else it will be a litmus test of whether the team - and in particular its current lead driver - has indeed made a crucial step forward. That, in turn, could help arrow in on why Kubica is struggling so much at times, and how he can address it.

"The key thing is we know so little about the tyres, we can't take them to a lab or measure what they're doing on the car, it's very difficult to understand what they're doing," says Robson.

"The driver is the best sensor on the car, in effect. Forget all the electronics, he's the most important bit on there. So, if what George is now able to do is really feel not so much what the tyre is doing now, but what it's going to do when he starts the timed lap [that is important].

"That's the other difficult bit, the outlap is so slow, you don't push the tyres and you've got to trust what the timed lap will be. The driver just plays a massive part. The upgrades will help him with that but so much comes down to him understanding it. And hopefully we see Robert get some assistance with that."

Recreating the exact conditions of the perfect storm of Budapest will be challenging, because whichever way you slice Williams's progress - week-to-week, the season as a whole compared to Hungary as one race, or dividing the 12 races so far into quarters - Hungary is a complete outlier.

The question for the team now is whether it was a fluke or a turning point. Spa may not suit Williams as well as the Hungaroring, but the team will have a key constant in the form of the upgrades that have improved the car's baseline performance, as well as Russell's own confidence.

"I'd like to think we can carry this through to future races," says Russell.

"I'm not convinced but I think we just need to be more dynamic to the situation and have less preconceived thoughts of how we need to approach something, and try more across the weekend. We haven't really tried enough different things, purely on the tyres, as we should have and that's something I regret slightly.

"But [Hungary] has definitely been a huge learning experience for all of us."