Vettel can match Schumacher's world title haul - Mario Theissen
The man who gave Sebastian Vettel his Formula 1 debut believes the German can go on to match Michael Schumacher's record haul of seven world titles after winning his third in Brazil.
Ex-BMW Sauber team principal Mario Theissen gave Vettel his big break in the 2007 United States Grand Prix.
"He certainly has a chance," Theissen told BBC Sport. "Anything can happen.
"He is one of the very few big names. If everything goes well, Sebastian has got another 10 years ahead of him."
Vettel finished sixth in a thrilling, rain-effected Brazilian Grand Prix after coming through from the back of the field following a collision on the first lap.
The position was enough for the 25-year-old to claim a historic third successive title and join a select band of eight other drivers - Schumacher, Juan Manuel Fangio, Alain Prost, Ayrton Senna, Nelson Piquet, Niki Lauda, Jack Brabham and Sir Jackie Stewart - to have won three or more world titles. Only Schumacher and Fangio had won three titles successively.
Theissen, who led the BMW Sauber team between 2006 and 2009, added: "Fangio dominated his era, Schumacher dominated his era and now I would say Sebastian, after that performance, has a good chance to become one of those heroes who really dominated - not just one season but four or five seasons."
The 60-year-old first encountered Vettel when he was BMW motorsport director, looking after the single-seater Formula BMW championship.
Then aged 13, Vettel shocked Theissen when he walked up to him and said: "I'm Sebastian, next year I will race in Formula BMW." Two years later, Vettel held true to his word and went on to win 18 out of 20 races on his way to the championship.
"He was quite different to the other boys," recalled Theissen. "When he arrived, it became immediately clear that he was very talented but also much more mature, focused and determined than other guys of his age.
"He's got a lot of the working ethic and determination of Michael Schumacher and this is something which has lasted throughout his career."
Vettel struggled to replicate that dominant form when he stepped up to the Formula 3 Euroseries and World Series by Renault, but his attitude was enough to persuade Theissen to give him a chance.
"He didn't have good results and it was different from what he expected," said Theissen. "But to watch him staying always focused, pushing and thinking about the next steps was impressive.
"It became clear to me, he would have the energy to stay ahead of the pack and to push forward in his career for many, many years. When we put him in the F1 car he proved immediately that he could do the job."
Vettel initially stepped up as the team's test driver from the 2006 Turkish Grand Prix and then impressed in his debut when standing in for the injured Robert Kubica at the United States Grand Prix, finishing eighth to become the youngest ever points scorer.
"Putting him in the car for that race was a risk," said Theissen. "But we were not fighting for the title so we didn't put any burden on him.
"We told him to take it easy and that's what he did. At the start, you could see he was inexperienced, very cautious. He tried not to damage car, lost a few positions, but then he drove a very solid race. That was in my view, the breakthrough. You could see he would be a strong Formula 1 driver."
Toro Rosso came calling shortly after that race and Theissen admitted "it hurt to let Sebastian go".
When asked what makes Vettel so successful, Theissen said: "He's focused. He is not interested in anything but racing.
"He understands that the role of driver extends beyond cockpit, the driver must lead the team and get them behind him and he must develop the car and show he is always pushing. I think that's what makes the difference."