Why F1's Class B is struggling to catch up

Were Formula 1's unofficial 'Class B' pack engaging in battle up front, the past three seasons would be celebrated as a time of dramatic performance swings, unpredictable races and ebbs and flows that made calling a winner on any given weekend almost impossible.

It's a difficult web to untangle. After all, how can you explain Ferrari-affiliated Haas slumping from fifth in the overall championship in 2018 (with the fourth-fastest car) to ninth in 2019, while Toro Rosso - also a small team benefiting from an alliance with a large operation thanks to it being Red Bull's junior team - had its best season in a decade and leapt from ninth to sixth with two podium finishes?

Understanding why some midfield teams succeeded and some underachieved reveals much about the art of making an F1 car, highlighting the differences between the three giants and the rest as we head towards a new season under a largely stable rules set.

The first factor is how closely matched the midfield is. In 2019, judged by qualifying pace and excluding the woefully-off-the-pace Williams, the six midfield teams were covered by 0.717%. That's narrower than the gap between the front of the midfield and the big three. So, performance swings can make a big difference and move a team in and out of contention.

Even this does not explain Haas, as it was just over a tenth of a percent slower in 2019 than 2018 relative to the front. Rapid throughout pre-season testing and in the season-opening Australian Grand Prix with a car developed aerodynamically by Dallara using the Ferrari windtunnel, the team's problems began to show in the second race in Bahrain, where Kevin Magnussen slumped from sixth on the grid to 13th at the chequered flag. Initially blamed on struggles with the tyres, it was eventually chased primarily to an aero issue that interacted problematically with the rubber.

"It was a combination of tyre and aero as they affect each other," says chief engineer Ayao Komatsu. "I'd say it was down to concept and correlation. The problem only became obvious when we got to hotter tracks. The consistency goes as we cannot keep the rear tyre working with the characteristics we have."

This manifested itself as a car with a strong front end, but which didn't deliver the anticipated downforce in slower corners even though things worked well in quick ones.

"The front is actually pretty good, but that gives you a problem with the balance as you have so much more oversteer," adds Komatsu. "When the tyres are new in qualifying, it's great and you can perform but in the race you can't keep the rears alive because it's not consistent through the corner. If you took that front end away, in the mid-corner you'd just have horrendous understeer so it couldn't be quicker. It goes back to correlation and concept."

The changes to the front wing regulations for 2019 - simplified wings with limited endplate geometry - is potentially the root of the problems, as Haas was locked into a car concept that it couldn't resolve. The situation was made more complicated by the fact the Spanish GP update made the problems worse and the team spent the middle stages of the campaign experimenting with early-season specs, which continued to run to the end of the year.

The team opted for the loaded outboard front wing concept, which offers greater potential for controlling the all-important aerodynamic wake off the front wheels but is more difficult to make work. It's no coincidence that this was the path taken by Renault, Haas, Racing Point and Williams - four midfielders that all struggled. It's not the wrong concept, just trickier, as Mercedes and Red Bull both thrived using it.

Toro Rosso's season was all about keeping things simple. This was its best season since 2008, matching its sixth place in the constructors' championship with what might be termed a lo-fi approach under new technical director Jody Egginton. Toro Rosso focused on maximising the use of non-listed parts (components that teams don't have to design themselves to qualify as a constructor), running the 2018 Red Bull gearbox and rear suspension - as well as the front suspension internals. This allowed Toro Rosso to focus on aero, as well as having a more reliable car. This pragmatic approach paid dividends with a car that was also more consistent than previous iterations.

"It comes down to a number of things," says Egginton of the squad's strong season. "The first thing is, it was the second year with Honda and starting earlier means you can really get the basics of packaging as you want, which gives you aero freedom.

"The parts we got from Red Bull and the synergy with them, even though it was from last year's car, allowed us not to worry about redesigning the gearbox main case, so that's the other benefit. It means you can redeploy that resource elsewhere in developing the car. Being supplied with parts allowed us, as a smaller team, to focus our resource on performance."

McLaren took a very different approach for its revival, which it hopes is the first step on a long-term plan to return to the very front. This was the result of some deep soul-searching, as well as major restructuring undertaken in June 2018. The arrival of team principal Andreas Seidl in May 2019 and technical director James Key shortly before that have contributed, but they are quick to underline that much of the firefighting had already been done.

"I only joined in March, but the team did a really good job of stepping back and having a very honest look at what the issues were," says McLaren technical director James Key. "It was a mix of some concepts that didn't really work aerodynamically or for what the car really needed - missing a few important points to where the trends were going. It's not necessarily a correlation issue, it's more that parts being brought maybe weren't relevant to what the car really needed. The team did a good job of stepping back from that and thinking, 'What did we get wrong, let's really understand this'.

"When I joined, it was still early days but the directions emerging were quite strong and seemed to be far more relevant to the balance characteristics the car needed. It's been a case of continuing down that road."

Renault's story is the inverse of McLaren's. While Toro Rosso was artificially close in the final standings due to two unlikely podium finishes, this was a season that failed to produce the anticipated progress for Renault. Team principal Cyril Abiteboul's pre-season target was to finish a stronger fourth and edge into the no-man's land behind the 'big three'. But the team slipped backwards - even though its pace relative to the front was actually fractionally better.

"It is not only front wing, it's front wing, it's nose, it's chassis winglets, bargeboards and everything - that whole system needs to work together," says Renault executive director Marcin Budkowski. "There's a trend towards unloaded outboard and it's fair to say we might have missed something there. The problem when you develop the front of the car around a concept is it's difficult to change. It's not changing the front wing as that's going to make you slower, you have got to change the whole front of the car."

This exposes the scale of the challenge for any team aiming to strike out towards the 'big three'. The vast amount of detailed aerodynamic science F1's big teams have built up is key to mastering this concept and Renault fell short. Upgrades didn't deliver what was expected, critically with the influential bargeboard area hitting a brick wall in terms of improvements. This, on top of the fact Renault is a rapidly expanding F1 team under huge board-level pressure to achieve, added up to a difficult year as it attempted to run before it could walk.

Racing Point didn't fall foul of this, but its necessary conservatism held it back. It only really picked up the pace in the second half of the season, performing well at Spa and Monza then, off the back of a Singapore GP aero update, for the rest of the year. Sergio Perez was the top-scoring midfield driver after the summer break, missing the points only once, but it was too little, too late.

"The whole change of ownership was happening around July/August [2018], and at that point you're making decisions on the architecture of next year's car," says technical director Andrew Green. "We didn't know what our resources were going to be so we made the decision to be safe and make sure we had a car on the grid and carried the concept of the chassis over, and a few other key concepts. We'd have been OK if we'd not had the change in wing regs as well. We didn't have the capacity to do a big study."

In the first half of the year, the problems manifested themselves as struggles in long corners, plus instability at corner entry - partly as a result of not having full control of the aero centre of pressure in the braking/turn-in phase, another area where the big teams have built vast knowledge.

Alfa Romeo started strong but faded and put its struggles down to being a 'young' team. While Sauber has been on the grid since 1993, it is in a rebuilding phase. But the team didn't build on a strong 2018. One factor that played a part is the struggle of replicating the performance of the tyres in windtunnels - using 60% models with a construction of tyre that changed in 2019. This is yet another area where the big teams found it easier to adapt.

"We struggled much more with the tyre deformation," says team principal Frederic Vasseur. "It's not easy to find a good compromise for the tyres in the tunnel and sometimes you can make a choice that can impact drastically on very slow corners or in the high speed."

As for Williams, much was wrong here. There were clear problems with Paddy Lowe's technical leadership of the team - hence his departure ahead of the season - with a big change in aerodynamic concept not delivering as hoped. The team, like McLaren, has taken a long, hard look at itself and anticipates at least being at the back of the midfield in 2020 - but it's so far off the back that it needs a big step. It's a reminder that, while some of the 'real' midfield teams hit troubles, it is possible to get things profoundly wrong. While others had the odd key failing, Williams suffered multiple problems.

That's the challenge for midfielders. They have fewer resources, therefore can do less research, understand less and struggle to respond if things go wrong - part of the reason that escaping F1's underclass is a huge challenge, even with the chances presented by the forthcoming 2021 rule changes.