The 2021 Formula 1 season begins tonight as cars hit the track for opening practice at the Bahrain Grand Prix.

It marks the start of what will be the final year of the current era for, while the engine formula is set to continue until 2025, sweeping new radical aerodynamic regulations promise to shake up the pecking order.

But before then, we’ve a record 23-race season to look forward to, and one which has a number of storylines to follow.

So before cars roll out of the garage for Free Practice 1 at 22:30 AEDT tonight, we bring you up to speed on what to watch for this season.

Mercedes vs Red Bull

Off the back of three days’ worth of testing, Red Bull looked to be the strongest team heading into the season-proper.

However, caution must be taken when reading into the pre-season results, as there are countless variables at play – least of them the teams’ propensity to sandbag.

There’s no hiding from the fact that Mercedes struck trouble; there was a gearbox problem for Valtteri Bottas on the opening day, and the car looked a handful.

Indeed, the team has conceded that it has a lively rear end, something they’ve spent the days since the test looking to understand.

Meanwhile, Red Bull topped two of the three days without issue, and had a very planted looking race car.

Those contrasting performances, and the swing we began to see at the end of 2020, suggest that perhaps – just perhaps – Mercedes’ domination is set to come an end this year.

Certainly it will have a harder time in the constructors’ championship, with Verstappen joined at Red Bull by Sergio Perez.

It makes for a tantalising set of circumstances in what could very well be Lewis Hamilton’s final F1 season (more on that below).

The midfield

Throughout the 2020 season we witnessed a fascinating battle for third in the constructors’ championship between McLaren, Racing Point (now Aston Martin), and Renault (now Alpine).

That feverish competition looks set only to ramp up this year, with even more teams likely to enter the fray.

Together with the trio from last season, Ferrari, Alfa Romeo, and AlphaTauri look to have made gains.

That potentially makes for six teams – 12 cars – battling over the crumbs left behind by Mercedes and Red Bull out front.

It will make any points-paying result critical as competition will be fierce, and prize money is paid out based on constructors’ championship results come season’s end.

McLaren looks as though it’s the top of that little battle pack, followed by the surprise package of AlphaTauri.

Ferrari will be somewhere there or thereabouts, likely ahead of Aston Martin, where there are concerns regarding the reliability of their car (Sebastian Vettel had issues on all three days of testing), and Alpine.

Williams could even make the odd appearance if its development plan pays off – though it’s expected to feature towards the back end of that pack.

Team leaders

Aston Martin and McLaren arguably both boast new team leaders for the coming season.

At the former, Sebastian Vettel is seen as something of a statement of intent from the team formerly known as Racing Point.

The operation has received a huge cash injection courtesy of new owners, leaving the 2018 nightmare well behind it.

Last year’s ‘Pink Mercedes’ controversy is also a thing of the past. The AMR21 shares similarities with last year’s car, but sports a raft of new bits which make it a bona fide Aston.

Alongside Lance Stroll, it will be interesting to see whether Vettel can push the team forward and, in turn, recapture a little bit of the sparkle he had during his early years with Ferrari.

Over at McLaren, it’s a similar story as Daniel Ricciardo partners Lando Norris.

A seven-time grand prix winner, Ricciardo offers something of a benchmark for exactly where McLaren is at after a couple of years spent rebuilding.

There’s all new management at the helm and fresh investment off track, not to mention a new power unit supplier in Mercedes.

They’re positive signs on the surface, and pre-season went well, but where Ricciardo winds up versus Norris – and Alpine (his old squad) – will be one to watch. Could he even be a legitimate podium challenger as some have suggested?

And then, of course, there’s Fernando Alonso, but more on him below.

Return of Alonso

Though he has won two world championships, it’s fair to suggest Fernando Alonso is a master of engineering his way into the right car at the wrong time.

He came close to titles with McLaren and Ferrari but was never able to find the sort of machinery he enjoyed in 2005 and 2006 (when he claimed titles for Renault).

It’s fair to suggest he will have another trying year as limited rule changes mean there’s little scope of a major reshuffle in the established pecking order.

Instead, look at how Alonso fares versus Esteban Ocon, a driver Ricciardo had the measure of in their season together last year.

If the Spaniard can match or better his French counterpart, it’s a sign that Alonso hasn’t lost his edge.

That will take time – he’s been out of F1 for two years – but by season’s end he really needs to be beating Ocon consistently if he’s to have any hope of a third world championship – assuming Alpine can deliver him a package capable.

Lewis Hamilton

On a one-year deal, there’s a chance this is the final season of seven-time world champion Lewis Hamilton’s career.

The changes set for next year threaten to upset the apple cart, and could offer the Brit a natural jumping off point.

Before then, there are a couple of milestones he could check off in 2021.

The biggest of those is the prospect of an eighth title, which would move him clear of Michael Schumacher as the most successful driver in F1 history.

He could also chalk up 100 wins, and 100 pole positions; he’s currently on 95 and 98 respectively.

They’re significant accomplishments, and could add a final coat of gloss to one of the sport’s most sparkling careers.

Year of the rookie

Three drivers are set to make their F1 debuts this weekend; Yuki Tsunoda, Nikita Mazepin, and Mick Schumacher.

Tsunoda will partner Pierre Gasly and comes with a handsome reputation as a rapid youngster with plenty of potential.

The Japanese driver has raced through the junior ranks and earned himself a berth in the sport’s top class.

Red Bull is a notoriously hard taskmaster, though at AlphaTauri he’ll be spared the worst of Helmut Marko’s wrath.

He’ll take time, but Tsunoda looks to be an extremely promising youngster with a bright future, if nurtured correctly.

Schumacher’s debut comes 30 years after his father had his maiden outing for Jordan at the 1991 Belgian Grand Prix.

At Haas, little is expected of the second generation driver, so gauging just how good, or bad, he is will be difficult.

That’s complicated because not only is the car expected to be rooted to the back of the grid, but he’s joined by Nikita Mazepin – another rookie.

It leaves a dearth of experience at the team as it looks to focus its energies on 2022, and promises to be an extremely character building year for both drivers.

But, somehow, the very best always manage to stand out. Schumacher’s father managed it in just a single event, and as part of Ferrari’s academy there is an expectation that his spawn has a little of that stardust.

Longest ever season

The 2021 season will be fought out over 23 races, the most the championship has ever had.

Among them are a couple of either new circuits, or circuits so old and reconfigured as to be new again.

Zandvoort last hosted F1 in the 1980s, though has been drastically overhauled since then.

It was meant to appear last year, but we all know what happened there, with its place on the calendar a result of F1’s rising popularity in the country courtesy of local hero Max Verstappen.

Also new is the street circuit in Jeddah, Saudi Arabia, which promises to be ultra fast.

Some have called it the fastest street circuit in F1, though that doesn’t do justice to the likes of Rheims, the AVUS, Pedrables, or a host of other venues from the sport’s decorated past.

Much of the season has been shoehorned into the second half of the year, covering off the risk still posed by coronavirus.

The effort required, and fatigue that will invariably accompany it, will be very real and managing burnout will be a key consideration for teams.

Cost cap

The days of Paul Stoddart and Ron Dennis trading insults during press conferences over the concept of budget caps are well behind us, and we are embarking on a brave new world for F1.

In truth, it’s something that should have happened back when Stoddy was running Minardi, as costs have escalated beyond stratospheric levels and made the sport unsustainable.

It will take some time for the full effect of the cap to come into play, but those at the front of the grid have certainly been hit harder than those at the back.

Exactly how that will manifest itself is less clear than the pecking order after pre-season testing, but in time it should help level what has been a very skewed playing field across the grid.

The 2022 conundrum

While there is a strong focus on being successful in this year’s competition, exactly when a team switches focus to next year is critical.

Too early and you’ll give up performance this year, but too late and you head into the new regulation set on the back foot.

Haas has already made its mind up, throwing the kitchen sink at 2022 and to damnation with 2021. Their car will get nothing in the way of updates in what is a big, bold, brave strategy.

A far more conservative approach will be taken by those racing for the championship, but how long they push on, and under the framework of the financial regulations, it could be a key factor in late season form, and 2022 success.

The next generation

Knocking on the door of an F1 berth is the sport’s next generation of racers, and that includes Australian Oscar Piastri.

Last year’s Formula 3 champion, the Melburnian has stepped up to Formula 2 with Prema for the coming campaign – the team with whom a certain Mick Schumacher won the title last year.

Piastri is a member of the Alpine Academy, which goes some way to easing his path into the big leagues should there be an opportunity, and his performances warrant it.

He’s not alone there – Christian Lundgaard is also part of that programme, as is Guanyu Zhou – but another season like last year and Our Oscar could leapfrog those two to stand first in line.

A poor season from Ocon or Alonso, and who knows what might happen for 2022?