Red Bull boss Christian Horner says that he's become increasingly impressed by Max Verstappen over the course of 2017.
He said that the young driver had gone through some tough times during the season, and that he had grown as a result.
"It is easy to forget it is only his fourth year of car racing," Horner pointed out.
"What has really impressed me this year is the way that he has dealt with some of the difficult moments. There have been quite a few of those, particularly in the summer months."
Verstappen suffered a string of retirements over the first half of the season. He finished only six times in the first 12 races. Many were related to the reliability and performance of the TAG Heuer-branded power unit.
At one point it seemed that Verstappen was considering giving up on Red Bull altogether. However, the season ended with a flourish that put the smile back on his face - and a contract extension in his pocket.
After crashing out in Singapore, he picked up his first win of the season next time out in Malaysia. Verstappen subsequently claimed a dominant victory in the Mexican Grand Prix later the same month.
"He has just grown in experience of racing in general. "He has kept working hard at it, he has kept the hours up on the simulator every week.
"His application is first class. And obviously his ability is unquestionable," Horner added. "He has a great feel for the car, a great sensitivity to the limit of the car."
That's not to say that Verstappen - who turned 20 in September - hasn't suffered a few youthful indiscretions along the way.
His collision with team mate Daniel Ricciardo at the Hungaroring was a particular low point. More first lap contact with Felipe Massa at Monza resulted in his lowest finish of the year, in tenth place.
"The moves in Hungary or Monza were the only two mistakes he has made this year," said Horner. "There is a fine line between hero and villain.
Horner said it was exactly this quality which made him such a favourite with Formula 1's fans across the globe.
"He is a risk taker, but not irresponsible risk," he explained. "Calculated risk. And he has a fighting spirit within him which is exciting to watch."