Lance Stroll says he would give himself "8.5 out of 10" for his rookie season in F1. Actually, the 19-year-old rookie has been roundly criticised this year, including by 1997 world champion Jacques Villeneuve who doesn't think Stroll has improved. "Looking at the season, I have to say there have been very challenging times. Especially at the beginning," said Stroll, whose billionaire father Lawrence brings substantial backing to Williams. "There were also some great times," Stroll insisted.