Lewis Hamilton has clinched his fourth Formula One world title and Jenson Button believes his former McLaren team-mate could go on to match Michael Schumacher's record haul of seven.
After being beaten to the title by fellow Mercedes driver Nico Rosberg in 2016, Hamilton ensured he will finish top of the drivers' standings for a fourth time on Sunday, a ninth-place finish at the Mexican Grand Prix enough for the Briton to open up an unassailable lead after nearest rival Sebastian Vettel came home fourth. The duo had collided on the opening lap.
Hamilton has now won as many titles as Alain Prost and Vettel, with Schumacher the only driver in the modern era to have accumulated more. Juan Manuel Fangio won five in the 1950s.
However, Button does not think a seventh world championship is necessarily out of reach for his compatriot should he remain in the grid's best car.
"You've just got to look at the stats. I mean, if we're going to do stats you'd say that there's only one person that's won more world championships [in the modern era] and that's Michael, Michael Schumacher," Button told Omnisport at an event to promote his new book.
"I don't think anyone ever thought that a driver would get close to seven world championships.
"Obviously, Lewis is equal with Alain Prost in terms of world championships. To win another three is asking a lot, but he's in a team that are very competitive. He's obviously still young and there is that possibility."
Hamilton has demonstrated superb form since the mid-season break to pull clear of Vettel, who has been plagued by reliability problems.
However, 2009 world champion Button is backing Ferrari to launch another solid bid for glory next year.
"Ferrari have looked strong this year. It's a shame they've had the reliability issues because it hurt the championship fight a little bit," Button commented.
"Ferrari will be strong next year, with Sebastian more so - that's what it seems the last couple of years - than Kimi, and Red Bull. They seem to have a power disadvantage compared to Mercedes and Ferrari but the car seems to be working well and they have two great drivers - Max [Verstappen] and Daniel [Ricciardo]."
Jenson Button's new book 'Life to the Limit: My Autobiography' from Blink Publishing is available now.