Formula One has decided to shake up its qualifying format at three races this year in a bid to improve the show. We take a look at what's changing and whether it will have the desired effect...
At three races this year, the grid for Sunday's grand prix will be decided by a 100km sprint race on Saturday instead of a traditional, fastest-lap-style qualifying session.
Sprint qualifying, as F1 has named it, will result in a race of roughly 30 minutes (17 laps of Silverstone, for example) with the potential to provide wheel-to-wheel thrills on Saturday and a mixed grid on Sunday.
The grid order for the sprint qualifying race will still be decided by a normal qualifying session on Friday afternoon (with the existing Q1, Q2, Q3 format) in place of a free practice session.
At the select rounds where sprint qualifying is used, the weekend format will be as follows:
First practice (60 mins)
Friday qualifying (60 mins - Q1, Q2, Q3 format)
Second practice (60 mins)
Sprint qualifying (100km race)
Grand Prix (305km race)
Which races will feature sprint qualifying?
F1 has decided to debut the new format at July's British Grand Prix before running it again at September's Italian Grand Prix. A third, non-European venue will be confirmed at a later date.
Interlagos in Sao Paulo is a suitable candidate for the third event and was at the top of F1's list for non-European venues, but uncertainty over whether the Brazilian Grand Prix will take place due to the aggressive rate of COVID-19 infections in the country means the sport will monitor how the pandemic evolves before committing.
Will points be on offer?
Points will be awarded to the top three drivers in the sprint race, with three for the winner, two for second place and one for finishing third.
F1 insists the focus of the weekend will still be on Sunday's race, and as a result a traditional podium ceremony will not be carried out after sprint qualifying.
However, by awarding points to the top three finishers there is a slim chance that a championship could be decided by the result of sprint qualifying rather than the result of a grand prix.
Such a scenario may upset purists, but plenty of championships have been won in the past by drivers picking up a handful of points in a lower ranking position without the glory of a top three finish.
Why change the format?
Since Liberty Media took over F1 in 2017, it has been researching new ways to engage audiences and improve the show.
In theory, more action results in more fans, which results in more revenue from TV and sponsorship deals.
Replacing one of the non-competitive practice sessions with a competitive sprint race seems like an easy win, and F1 is confident it will broaden the appeal of a race weekend.
"The thing to remember about Sprint Qualifying is that it's intention is to expand the whole weekend," F1's motorsport director Ross Brawn told F1.com. "It is not intended to impact the race event. The Grand Prix is still the vital event of the weekend.
"We want to give fans engagement throughout the whole weekend. Sunday's Grand Prix is fantastic, and we don't want to cannibalise that, but we want to lift up the engagement on a Friday and a Saturday.
"Friday is really for the aficionados at the moment. Watching practice session on Friday is fun but there is no conclusion to it. But on a Friday now [at these selected events], we'll have the excitement of the qualifying format."
What happened to reverse grids?
Those following F1's news cycle over the last year will remember that the sprint qualifying idea started life as a proposal for a reverse grid race on Saturdays.
The reverse grid format was similar to sprint qualifying, but the starting order for Saturday's sprint race would have been set by reversing the championship order rather than holding a Friday qualifying session.
In theory, it would force the fastest drivers to fight their way through the pack to secure the best possible place on the grid for Sunday's race.
The idea gathered some support among smaller teams but was panned by senior drivers, such as Lewis Hamilton and Sebastian Vettel, and was ultimately blocked by world champions Mercedes.
Mercedes' concern was that it would add a gimmick to the weekend that was at odds with the core principles of F1, and that the sport wasn't in need of such a radical shake-up in the first place.
The 2020 Italian Grand Prix, won by AlphaTauri's Pierre Gasly after a red-flag stoppage mixed the order ahead of a mid-race restart, was used as an example of how exciting reverse-grid racing could be, but the comparison was dubious and failed to win over the skeptics.
Mercedes team principal Toto Wolff summed up the argument against reverse grids by saying: "This is not WWE."
Will sprint qualifying work?
If F1's objective is to offer more exciting track sessions over a weekend, removing a non-competitive practice session and replacing it with a sprint race is a clear win.
But the jury is still out on whether sprint qualifying will provide exciting racing and there is also the potential for some downsides for the championship as a whole.
As with F1's traditional format, the fastest cars from single-lap qualifying will still start at the front of the grid for the sprint race and there's a good chance that, because they are the fastest cars, they will retain their position at the front throughout the race without much change in the order.
It's an age-old issue for motor racing, and the thing the original reverse-grid idea was trying to combat.
What's more, a shorter race without pit stops will create fewer opportunities for strategic variation, which is also likely to result in a follow-the-leader outcome.
Think of some of the most exciting grands prix in recent years, and they only really kicked into life in the second half of the race once tyre strategies started to impact the relative performance of the cars.
It's often the case that overtaking occurs in F1 because the two cars racing each other are using different tyre compounds or different ages of tyres or both -- those factors are less likely to come into play over a 100km race.
F1 may point to the Drag Reduction System (DRS) as a way to give the chasing car an opportunity to overtake, but simulations of sprint races run by the teams suggest that may not be the case.
The DRS is an overtaking aid that allows a driver to increase their car's straight-line speed by opening a flap in the rear wing to reduce drag.
The DRS can only be activated in certain zones around the circuit and, in race conditions, only when a driver is within a second of the car in front.
In theory, the extra straight-line speed of the car using DRS will help it overtake the car in front, but when you get a long line of cars all within a second of one another -- known as a "DRS train" -- the advantage is often negated for all but the car at the lead of the pack, which is usually the fastest one anyway.
There were suggestions the use of DRS could be extended to cars that are two seconds behind the car in front, but there was no mention of that in Monday's announcement and it's not clear it would have a major impact anyway.
In terms of mixing up the grid for Sunday, there's more potential for a retirement or accident in a sprint race than there would be in a normal qualifying session, and that could leave a competitive car fighting back through the field in the main event.
But the danger of dropping to the back of the grid with a mistake in the sprint race may have an impact on the style of racing we see on Saturday afternoons, with drivers less likely to risk an overtake in the knowledge that far more points are on offer for a good result in the grand prix than an extra position in sprint qualifying.
When weighing up the trade-off between moving up one grid position and a potential back-of-the-grid start, it's easy to imagine engineers telling their drivers to hold position.
What's more, an incident in a Saturday qualifying race could have major implications for the championship.
While the prospect of a runaway championship leader having to fight back from a Saturday accident in Sunday's race is appealing, there's also the possibility of a rival driver dropping out of championship contention because a car issue on Saturday leaves him down the grid for Sunday's race.
Of course, the same could be said of a mistake in traditional qualifying, but the risk of putting it all on the line for a single lap are not as great as doing so over a 100km race.
As a result, we may just see conservative processions during the sprint races unless a driver finds himself way out of position after Friday qualifying.
Did all the teams agree to the new format?
Sprint qualifying gained unanimous approval from the ten teams, the FIA and Formula One itself, but it required an "extensive consultation and review process" to get to that point.
The discussions included providing the teams with a bonus payment from F1 for taking part in the three sprint races as well as a damage allowance within F1's budget cap so that any repair bills as a result of the extra sprint races do not put added pressure on teams already struggling to comply with the $145 million cap.
Will it be rolled out at all races in the future?
F1 is treating this year's three sprint qualifying sessions as a trial before deciding whether to apply the idea at more races in the future.
However, Brawn confirmed that it would not be used at certain venues, such as Monaco, where overtaking is rare and single-lap qualifying is already an impressive spectacle.
"I'm not sure this format would be as successful at Monaco," he said. "We're considering these weekends being Grand Slam events, spread through the season, so it is something different.
"I don't think it'll go to the whole season, I think it'll be a limited number of races, but that is to be decided."
Brawn added: "The drivers are open minded about the format -- and that's all we ask, that the drivers keep an open mind so we can evaluate this event and then we decide if in the future it forms a feature of the F1 season.
"If it doesn't work, we put hands up and we will think again."
The complicated bits: Wet weather, tyres and parc ferme
In changing the format, F1 had to take into account the potential knock-on impacts of wet weather, use of tyre allocations over the weekend and the need to extend parc ferme regulations over three days.
One quirk of the new regulations is how it will impact the use of tyre allocations over the weekend.
Three different dry weather tyre compounds are provided to the teams at each race, with each driver receiving eight sets of softs, three sets of mediums and two sets of hards at a normal weekend.
That allocation has been tweaked for the sprint qualifying format, with six sets of softs, four sets of mediums and two sets of hards available to each driver.
Soft tyres usually provide the fastest lap times but come with the compromise of a shorter life in race conditions, while hards have the longest life but the worst performance over a single lap.
In a traditional qualifying format, soft tyres are almost always the best to achieve a fastest lap, but ideally fresh tyres are fitted for every run.
In sprint qualifying the medium or the hard tyre is likely to be the better option, with just a single set used to avoid making a pit stop.
As a result, the rules over tyre usage have been changed for sprint qualifying weekends with the following allocation for each session:
First practice: A free choice of two sets of any tyre compound.
Friday qualifying: Five sets of soft compound tyres for use over Q1, Q2, Q3.
Second practice: Free choice of a single set of any tyre compound.
Sprint qualifying: Free choice of up to two sets of any tyre compound -- no mandatory pit stop required. The set of tyres that has completed the most laps from the sprint race will be returned to Pirelli after the session.
Race: Free choice of remaining tyres -- mandatory use of at least two tyre compounds in dry conditions, meaning at least one pit stop.
The use of soft tyres only in Friday qualifying means F1 has scrapped the rule that said drivers qualifying in the top ten are required to start Sunday's grand prix on the tyre they used to set their fastest lap in Q2.
As a result, all 20 cars will have a free tyre choice for the start of the grand prix.
If first practice or Friday qualifying is held in wet conditions, teams will be given an additional set of intermediate tyres on top of their usual allocation of four sets, but they must then return a set of used intermediates before the start of sprint qualifying.
If sprint qualifying is wet, the teams may return one set of used full-wet or intermediate tyres after the session, to be replaced with a new set ahead of Sunday's grand prix.
Do the math, and there is the potential for the normal allocation of seven sets of wet weather tyres (three sets of full-wet tyres and four sets of intermediates) to increase to nine sets over the weekend.
F1 has long had parc ferme regulations between qualifying and the race, under which car setups cannot be changed.
The original idea was to ensure teams do not turn up to circuits with one car configuration for maximum performance on a single lap and a completely different one for the race, which has the potential to increase costs significantly.
Under the new format, parc ferme regulations will be applied from the start of Friday qualifying, through Saturday's sprint qualifying and into Sunday's race.
However, certain aspects of parc ferme will be lifted to allow alterations for the second practice session on Saturday morning before car configurations are returned to parc ferme specification for sprint qualifying. The idea is to make sure the Saturday morning practice session is still valuable for teams wanting to test developments.
Some small changes to specific elements of car setup will still be allowed under parc ferme, such as cooling changes if the temperature changes by 10C, some suspension changes and replacement brake material for safety reasons.
What's more, if a team damages a component in sprint qualifying, such as a front wing, and does not have any spares of the same specification, it will be allowed to replace it with an older, previously-used specification without incurring a penalty.