Is Lewis Hamilton the greatest Formula 1 driver of all time in the wake of his fourth world title? Is he even in the top five?
Comparing sportsmen of different eras with accuracy and objectivity is difficult enough at the best of times, but especially so in motorsport, where machines play a huge role in determining results.
Nevertheless, the cream tends to rise to the top and the best drivers of each generation usually find themselves a seat in the fastest teams, winning races and titles.
At the pinnacle of car racing, greatness is often determined by the unforgettable rivalries over different eras and the drivers who are able to prove their dominance over the toughest opponents.
Here are some of the finest drivers the sport has known. How does Hamilton compare?
Juan Manuel Fangio (active 1950-58)
- World titles: 5
- GP wins: 24
- Pole positions: 29
Having learned his craft in the long-distance races in tough conditions in South America, Fangio went on to dominate the glitzy, Euro-centric world of Formula 1 like nobody before or since.
The Argentine's 24 wins came from just 51 races and he won five titles in his seven years in the sport. Already in his 40s when he won his first championship, Fangio showed a canny ability to find himself in the best ride each year. He won titles with Alfa Romeo, Maserati, Mercedes and Ferrari.
Above all, though, he was a sensationally talented race car driver, again and again defying belief to win races that seemed unwinnable, including a final, legendary performance at Germany's Nurburgring in 1957 where he drove at speeds never seen before in Formula 1 to chase down the two Ferraris in front of him and secure a fifth title.
He was Ayrton Senna's idol.
"What he did in his time is something that was an example of professionalism, of courage, of style and as a man, a human being," the Brazilian ace said.
No wonder they called him "Maestro".
Sir Stirling Moss (1951-61)
- World titles: 0
- GP wins: 16
- Pole positions: 16
With a successful background in touring cars and rallying, Moss was no doubt one of the most naturally talented drivers to have ever taken the wheel.
"Mr Motor Racing" became Fangio's biggest rival when both were at Mercedes and after the Argentine's retirement in 1958 he stood head and shoulders above everyone else in the sport.
The fact he never won a world title ranks as the most incredible statistic in Formula 1, and had much more to do with his loyalty to English teams than his driving ability.
His 16 wins, often pulled off in far inferior cars pushed well beyond their limits, left fans in no doubt of his superiority on the track.
"If everything is under control," he once said, "you are just not driving fast enough."
Jim Clark (1960-68)
- World titles: 2
- GP wins: 25
- Pole positions: 33
Unlike Moss, the man who he replaced as the world's best driver, Clark's statistics do tell the tale of just how good he was. His win percentage (25 in 72 starts) is only bettered by Fangio and Alberto Ascari, while he was on pole for 45.2 per cent of his races.
During his reign in a frighteningly quick Lotus, he blitzed every other driver in the field in a display of dominance not seen again until Schumacher romped to title after title.
Clark raced at unholy speeds at a time when Formula 1 was incredibly dangerous for all involved. In the end motorsport would take his life: he was killed when he crashed his Lotus into trees at a wet Hockenheim track in 1968 during a Formula 2 race.
Bruce McLaren lamented the loss of the legendary Brit.
"Jimmy ranked with, perhaps even out-ranked, Nuvolari, Fangio and Moss and I think we all thought that he was in a way invincible. To be killed in an accident with a Formula 2 car is almost unacceptable."
Alain Prost (1980-93)
- World titles: 4
- GP wins: 51
- Pole positions: 33
He may be best remembered for his intense and spiteful rivalry with Senna, but Prost stands alone as one of the greats of F1.
Known for his smooth, almost flawless driving, the Frenchman earned himself the nickname "Le Professeur" as he finessed his way to four titles.
"I have always had this mentality because I hated to break anything on the car," he said.
Like any sportsman possessed of immense natural talent, Prost almost made racing look too easy. While Senna attacked the track, Prost took him on and often beat him while barely seeming to raise a sweat.
The pair's disdain for one another probably had a lot to do with the fact they couldn't comprehend what made the other tick.
Ayrton Senna (1984-94)
- World titles: 3
- GP wins: 41
- Pole positions: 65
Aggressive, fearless and unbelievably quick, there is no doubt Senna would have won multiple world championships in whatever era he raced in.
He rattled the experienced Prost from the very start of his career and went on to shake up all of Formula 1 until his death at the age of 34 at the 1994 San Marino Grand Prix.
His racing philosophy summed up everything about his career and its tragic end.
"You are doing something that nobody else is able to do," he said. "(But) the same moment that you are seen as the best, the fastest and somebody that cannot be touched, you are enormously fragile. Because in a split second, it's gone."
His white-knuckle style of driving saw him anger rivals but dominate in the toughest conditions. He won at Monaco six times and put in mythical drives in the wet at Estoril and Donington Park.
He was killed pushing his car past its limits while trying to hold off a young Michael Schumacher to send his native Brazil into mourning. Millions of Formula 1 fans around the world, convinced of his immortality, were heartbroken.
Michael Schumacher (1991-2012)
- World titles: 7
- GP wins: 91
- Pole positions: 68
Statistically, Schumacher reigns supreme in the history of Formula 1. The German combined many of the best traits of other world champions into a formidable driving package. He was ruthless and clinical but could turn on the aggression when needed.
After winning titles with Benetton in 1994 and 1995, he went on to drag the hugely popular Ferrari team out of mediocrity and made it a world-beater again, winning five straight championships with the Prancing Horse and becoming an idol in Italy.
He may have had everything in his favour during much of that success — superior cars and tyres and the lack of a great rival for a sustained period — but it was Schumacher's strength of will that continued to drive him to relentless success.
"The more precisely I can drive, the more I enjoy myself," he said.
Lewis Hamilton (2007-)
- World titles: 4
- GP wins: 62
- Pole positions: 72
The way Hamilton reeled in championship rival Sebastian Vettel in 2017 before blowing him away in the latter part of the season should settle any questions over who the finest driver of the current era is. Vettel may have four titles to his name, but this was the first season he faced a worthy challenger in a car that matched his own — and the German was clearly outdone by the Brit.
Hamilton has an ego to match any of the big names of bygone eras, and as his career progresses he has shown he has the ability to back it up.
A relaxed character off the track, when racing he becomes a snarling beast, striking out at any driver who dares to cross him and even his own team when they can't match his skill and ambition.
Hamilton always said he would be content if he matched his hero Senna's three championships. Now he has four with the prospect of more to come.
"It's very surreal," he said after wrapping up the title in Mexico. "Hard to believe. I feel incredibly grateful and at peace in my heart."