Former Red Bull motorsport adviser Dr Helmut Marko has branded the 2021 Formula 1 season as the "toughest year" during his time in the championship.
The 82-year-old left his role at the Milton Keynes outfit at the end of 2025 after a 20-year stint. Having raced in the championship from 1971 to 1972 and founding RSM Marko in 1984, which later became the Red Bull Junior Team, the Austrian has been involved in the series for over five decades.
Reflecting on his career during an interview with F1 Insider, Marko expanded on why he thought the 2021 season was his most challenging. That season ended with Max Verstappen claiming his first of four championship titles after an intense battle with seven-time champion Lewis Hamilton.
Although the 2021 Abu Dhabi Grand Prix has gone down in the history books as one of the most controversial moments in the championship, Marko also pointed to other "toxic" moments of the season.
"2021 was, in terms of emotions, politics – in terms of everything, the toughest year I've ever experienced in Formula 1," he said. "Mercedes dominated.
"Suddenly, Red Bull came along with a relatively young driver and challenged everything. There were collisions on the track – the first at Silverstone, where Hamilton's front wheel hit Max's rear wheel, he flew off at over 300 km/h.
"But there was also a sometimes toxic atmosphere off the track. Political intrigue everywhere. Really, really tough. Then the finale in Abu Dhabi, which went in our favour – partly because we changed the tyres at the right moment. At Mercedes, the fact that they lost that World Championship is still deeply ingrained."
Mercedes won the constructors' title, but Hamilton missed out on his eighth drivers' championship title. The British driver was leading the race with Verstappen following in second before a crash by Nicholas Latifi brought out the safety car.
With the chequered flag closing in, Hamilton looked set to claim the championship. But race director at the time, Michael Masi, ordered only the lapped cars between Hamilton and Verstappen to unlap themselves in order to have enough time to go racing again; allowing all lapped cars on the grid to do so would have resulted in the race ending under safety car conditions.
After the safety car returned to the garage, Verstappen, who was on fresher tyres, was able to overtake Hamilton to take the title.
The decision from Masi was, and continues to be, a point of debate among fans and the paddock.
