Paris - Lewis Hamilton and Sebastian Vettel start the Formula One season in Australia on March 25 within touching distance of further greatness.
A fifth world title would move one of the drivers level with Juan Manuel Fangio and second only to Michael Schumacher's seven.
Hamilton and Vettel share 109 wins (Hamilton 62, Vettel 47), 216 podiums (117-99) and 122 pole positions (72-50).
Hamilton got his first title 10 years ago before Vettel won four straight from 2010-13.
But Hamilton has dominated since joining Mercedes. Last year's title was the British driver's third in four seasons to level at 4-4 with his Ferrari rival.
Next Sunday's season-opening Australian GP will be Vettel's 200th race, and fittingly the German is seeking his 100th F1 podium. Hamilton, meanwhile, seeks a record-extending 73rd pole and a 63rd GP win.
Matching Fangio, the daring Argentine who won his titles in the 1950s when driving circumstances were extremely challenging, will make one of them truly stand out.
"(He was) the best we've ever had in terms of putting it all together," Vettel said of Fangio, while Hamilton described him as "the godfather of the sport" driving in "the most dangerous period of time."
F1 is far more safety-conscious these days, and risk-taking on track has greatly diminished. Still, this did not stop Vettel and Hamilton clashing last season. Gaining any sort of psychological advantage can prove important, considering they are hugely successful in their own right.
The 33-year-old Hamilton has the edge with 47 wins and 50 poles but is three years older than his rival.
"It gets harder and I love that challenge. I love that I'm faced with this huge mountain to climb again," Hamilton said.
"I've got to work harder than I've done before. Physically I'm stronger, I've put on muscle. I feel very strong mentally."
Although Hamilton has yet to sign a new contract with Mercedes, fuelling talk he could walk away from F1 to pursue other interests at the end of the season, his hunger is still evident. Only Schumacher has more wins with 91.
Taking inspiration from veteran stars, such as 20-time Grand Slam champion Roger Federer, helps Hamilton hit his targets. Persuading himself he's the best is an important part of that success.
"That's what you have to think. I'm sure if you asked Federer, he will truly believe that if he's trained hard and feeling great, there's no one that can touch him," Hamilton said.
"You have to be convinced that will be the case."
Hamilton is friends with another tennis star, Serena Williams, who like Federer is 36. Hamilton clearly draws inspiration from athletes who have pushed back time.
"I look at these greats who continue to break barriers within their own performance. (I) keep going back to Federer, but he's back at the top," Hamilton said.
"To have that drive: You've got family, you've got wealth, but still have that drive - maybe it is part of the mark of a great. It's inspiring to see these iconic individuals continue to shine, and they're inspiring."
But even Hamilton concedes there are limits.
"I was playing tennis with my dad, trying to be Federer," Hamilton said. "I sucked, but it doesn't mean I can't try."
On the track, challenging Vettel will prove an arduous fight.
The 30-year-old has a huge point to prove this year after the way he capitulated at the Singapore GP last year.
Vettel was only three points behind Hamilton in the championship with seven races remaining. But he crashed from pole position and the nightmare scenario saw Hamilton win the race. It was the turning point of the season and Vettel never recovered.
"I can't wait to be in Australia," Vettel said.
"I have confidence in our car I have a lot of confidence in our team, I know how skilled and committed the guys are."
As well as each other, Vettel and Hamilton - who won 14 of 20 races in 2017 - should also keep an eye on their wing mirrors this year.
Pre-season tests indicated Red Bull will be faster and - crucially - more reliable this time round.
Last season, drivers Max Verstappen and Daniel Ricciardo failed to finish a total of 13 races between them, an alarmingly high total for the team which won four straight drivers' and constructors' titles from 2010-13 with Vettel.
But crashes aside, Red Bull also won three races, as many as Hamilton's team-mate Valtteri Bottas in a quicker and more trustworthy car.
With extra speed and consistency, Red Bull could be challenging for victory in a lot more races. They have two hungry drivers jostling to be No 1 within their own team, which will add spice to the championship.
"Mercedes are probably just in front of us but Ferrari I'm not sure," Ricciardo said.
"But I think we're going to be much closer than last year."
There will be some new faces on the grid in Melbourne.
F2 champion Charles Leclerc - a highly rated 20-year-old who came through Ferrari's prestigious drivers' academy - is racing for Sauber. Making his debut for Williams will be 22-year-old Russian driver Sergey Sirotkin.
Meanwhile, Fernando Alonso will find out if it was worth his McLaren team changing engines from struggling Honda to Renault. If the 36-year-old Spaniard fails to add to his 97 career podiums - the last was with Ferrari in 2014 - this could well be his final year in F1.
The two-time F1 champion makes no secret of his ambition to win the Indianapolis 500 and the 24 Le Mans 24 endurance race.