#3 Lewis Hamilton has lost to his teammate on numerous occasions
Can you be considered the GOAT if, at some point in time, you were beaten by your own teammate driving the same car?
Let's be honest, Lewis Hamilton has had a great career. He was promoted to Formula 1 against the reigning two-time world champion and beat him in his rookie year. That's the stuff legends are made of.
But then, somewhere down the line, Lewis Hamilton also lost to his teammate Jenson Button in the drivers' standings in the 2011 season. In fact, during their time together across three seasons, Button outscored Lewis Hamilton 672 to 657 points.
How good was Jenson Button? He was a world champion in his own right.
Something similar happened in 2016 when Lewis Hamilton lost the world title to teammate Nico Rosberg.
Again, Nico Rosberg is not a bad driver by any means, but when you are in the reckoning to be the GOAT, you can't lose to drivers driving the same car.
#4 Michael Schumacher was the undisputed rain meister
When one talks about Michael Schumacher and the best races he ever drove, the wet race in Barcelona 1996, his scintillating performance before he crashed in the rain at Spa in 1998 and many others come to the fore.
In these races, Michael Schumacher use the rain to mask the deficiencies of his car to dominate the field.
One of the true measures of a Formula 1 driver's pedigree is how he drives in the rain. Michael Schumacher, throughout his career, was the standout driver in the rain, with no one coming close to him.
Lewis Hamilton, to his credit, has had some sensational wet weather victories in his resume as well. He dominated the race in treacherous conditions at Silverstone in 2008. Hamilton also put together a brilliant display at Suzuka in 2014 and Brazil in 2016.
However, Lewis Hamilton has had his fair share of poor wet weather races as well. Be it the Australian GP 2010, Canadian GP 2011, Hungarian GP 2011, Malaysian GP 2012 or even the Chinese GP 2010, which his teammate Jenson Button won.
Sure, Lewis Hamilton has won multiple wet weather races, but he's had some terrible ones too.
#5 Lewis Hamilton hasn't had much competition during his title triumphs
Michael Schumacher won his first world title against Damon Hill, a world champion, in a seesaw battle.
He won his third against two-time world champion Mika Hakkinen in a similarly paced McLaren. His sixth title in 2003 saw him fight off the likes of Kimi Raikkonen and Juan Pablo Montoya from two different teams in the final race of the season.
Meanwhile, Lewis Hamilton barely won his first title against Felipe Massa on the last lap of the season in a similarly paced Ferrari. Hamilton's second and third title triumphs were against Nico Rosberg, and the rest of his championship victories saw him dominate the field with a much faster car.
Sure, many would say that Ferrari was a competitive adversary in the 2018 season. But if we delve deeper, we'll find that Mercedes scored 13 of 21 pole positions and won 11 out of 21 races in 2018. They were in a class of their own in 2018 as well as they cantered to another world title.
Lewis Hamilton has indeed had a stellar Formula 1 career. If he wins a record-eighth title, he will surely go down as one of the most successful in having graced the sport. But would he necessarily be called the greatest ever?
One would think Michael Schumacher has better credentials than Hamilton.