Formula 1 motorsport boss Ross Brawn believes Lewis Hamilton has now established himself as the “strongest” driver of the last 15 years after winning his sixth world title.

Hamilton clinched his third consecutive world championship and the sixth of his career with a second-place finish in Sunday’s United States Grand Prix to move to within touching distance of matching Michael Schumacher’s all-time record of seven world titles.

Brawn admits he initially had doubts over Hamilton’s approach when he started working with him in 2013, but feels the Briton has grown considerably en route to claiming five of his six titles with the German manufacturer during the V6 hybrid era.

“It’s hard to find anything new to say about the trajectory of Lewis Hamilton’s Formula 1 career,” Brawn said in F1’s US GP media pass.

“One could let the statistics do the talking but that would be a rather dry way of acknowledging his sporting greatness.

“Therefore, I think the best compliment I can pay Lewis today is to say that he has found a unique way of being a great champion.

“I have to admit that when I started working with him back in 2013 I was slightly nervous about his approach to being a professional racing driver.

“For me, the benchmark was Michael Schumacher, a man totally dedicated to chasing success and at the same time very keen to guard his privacy and that of his family.

“Even then, Lewis was demonstrating a truly eclectic approach to his career and whilst totally professional he preferred a lifestyle that was definitely less monastic than Michael’s.”

Brawn praised Mercedes boss Toto Wolff for his management style and handling of Hamilton’s off-track activities and personal life, which he reckons has been a huge factor behind Hamilton’s success.

“Lewis has always been comfortable moving in different circles, such as music and fashion, and that’s given him the energy to develop his talent still further, while always ensuring he is in the best physical shape possible, which is vital in the modern Formula 1 era,” he added.

“And at Mercedes, Lewis has found the right support in an environment that is stimulating technically but that at the same time allows him the freedom he absolutely needs.

“I therefore congratulate Toto Wolff and the whole team, as they’ve not only given him an amazing car year after year but they’ve allowed Lewis to develop and grow to become one of the greatest drivers in the history of Formula 1, certainly the strongest of the last 15 years.”