Stewart competed for nine seasons in Formula 1 across the 1960s and 70s, winning three championships - he was the only Brit to achieve this until Lewis Hamilton matched him in 2015.Verstappen is on course to win his third in a row this year, but Stewart insists that today’s F1 is easier to conquer.“Because there are a lot more races,” he told Bild. “When I became world champion for the first time in 1969, we only competed in 11 grands prix. This year the calendar consisted of 24 races [although two were cancelled]. “Given the number, you can afford to have a…