Nick Heidfeld believes Max Verstappen is now the "complete Formula 1 driver" as he closes in on becoming a triple World Champion.
Verstappen can seal his third title in Qatar next weekend and has become the 'man to beat' in F1 over the last three seasons, and has won 13 of 16 races in the 2023 season.
Heidfeld was a F1 regular between 2000 and mid-2011, racing for the likes of Prost, Sauber, Williams and BMW, before leaving Lotus after the 2011 Hungarian Grand Prix.
He claimed 13 career podiums, including a record eight-second places which makes him the most successful driver in terms of podiums without a win.
A career in Formula E and sportscar racing followed for the man known as 'Quick Nick', who feels Verstappen has morphed into a unstoppable force.
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'Verstappen the complete driver'
"It is very impressive what Verstappen is doing, his talent has always been undisputed," Heidfeld told Sport1.de.
"On track, you can see that he is special, even compared to other top drivers. Something that has surprised me, in a positive sense, is that he has learned from his mistakes and has developed extremely [well]. He is a complete Formula 1 driver.
"Really, only a few are as special as Verstappen, very, very few drivers.
"You had Michael Schumacher. When I was still driving in Formula 3000 (today's Formula 2), I looked at the F1 cars in Monaco.
"To this day I keep saying it: 'If you look at all the cars and If all helmets had been painted the same colour, you would still have been able to recognize Schumacher. He simply drove in a different way. He had more control over his car and drove closer to the walls.
"Lewis Hamilton had extremely good control over his car but was a bit wilder than Schumacher, and Fernando Alonso also caught my eye then.
"He may not have driven so close to the walls, but he was incredibly consistent and had great control over his car."
"You shouldn't forget Sebastian Vettel [either].
"Things [were a bit quieter in terms of results] in the last few years of his career, but during his Red Bull days, I remember that he once drove a qualifying lap in Turkey and I thought: 'Wow, [that's] really crazy!'"