Nico Rosberg's decision to announce his retirement from Formula 1 just five days after clinching his first world title is a major shock - but perhaps it should not be.

The German put everything into this season, as he explained in his statement on Friday. The pressure of those last few races was plain to see in Abu Dhabi on Sunday, in the way it peeled off him by degrees in the hours after the race.

While thinking about how hard winning that title was, doubtless his thoughts were also about what it would take to beat Lewis Hamilton to it again. He clearly felt that at the age of 31, with a young daughter, he was not prepared to make those sacrifices again.

All in all, it is a classy move from a classy man.

http://m.bbc.com/sport/formula1/38185846