Lewis Hamilton put the final touches on his remarkable season by winning the concluding round of the year in Abu Dhabi on Sunday.

After 21 races, the Formula One circus now heads for its winter hibernation before next year’s opener in Melbourne on March 17.

Here, Press Association Sport identifies some things to look out for in 2019.

Who will take the fight to Hamilton?

Max Verstappen scored more points than any driver bar Hamilton following a strong finish to the year. If Red Bull get their act together over the winter, we could see a fascinating three-way battle for the championship. Hamilton, however, must be the favourite to win title number six.

Vettel must bounce back from difficult year

For all of Hamilton’s brilliance, the Briton’s championship challenge has been aided by Vettel’s collapse. Indeed, the Ferrari driver has not won since August’s Belgian Grand Prix. For much of the second half of the year, Vettel, who made a series of mistakes, looked a doomed man. In Abu Dhabi, he admitted he was looking forward to getting away from it all. How he bounces back next year will determine the four-time world champion’s legacy in the sport.

Bottas will be looking over his shoulder if results don’t improve

While Hamilton won 11 times for Mercedes this year, Valtteri Bottas failed to stand on the top step despite driving the same machinery. He finished fifth in the championship, an eye-watering 161 points behind Hamilton. Yes, China (a late safety car), Azerbaijan (a late puncture), and Russia (ordered out of Hamilton’s way by Mercedes) are examples of victories that got away. But Bottas cannot hide from the fact that he has gone off the boil in the second half of the year. Esteban Ocon, bumped out by Force India, will be the reserve driver at Mercedes next year, and Bottas’ seat will be under severe scrutiny if he fails to raise his game from the kick-off in Australia.

Battle of the junior Britons

George Russell and Lando Norris will increase the tally of British drivers to three next year with their respective moves to Williams and McLaren. Both Russell, 20, who clinched the Formula Two championship in Abu Dhabi on Saturday, and Norris, 19, who finished as runner-up, are rated as stars for the future. Yet both rookies will be seeking huge improvement from their new teams over the winter. Williams finished last in the constructors’ championship this season, while McLaren’s failings were exposed again following a desperately underwhelming year. Both must do better.

British GP future hangs in balance

As it stands, next season’s British Grand Prix will be the last staged at Silverstone. The British Racing Drivers’ Club – owners of the Northamptonshire circuit – triggered a release clause in the hope of renegotiating a more financially feasible deal. Yet, some 16 months on, a new contract with F1’s owners, Liberty Media, is some distance from being finalised. Silverstone are hopeful of getting a deal over the line, while Liberty do not want to lose races from the sport’s traditional European heartland, but do not be surprised if this saga rumbles on for at least another year.