As for why he retired when he did, I was as surprised as anyone by the news. On reflection, however I think it’s fairly simple: the truth I think not even Nico would deny is that Lewis is, all round, a fractionally quicker driver, and a better racer too. Rosberg’s championship saving move on Max Verstappen showed how brave he could be at the most critical of times, but over a season and all other things being equal, I think most people would expect Lewis to outpoint Nico most of the time. This season all other things were not equal and had the two Mercedes drivers enjoyed the same reliability records, it would be Lewis who’d have captured his fourth world title, rather than Nico his first.
So Rosberg would have calculated that while things went his way in 2016, the cards were probably unlikely to fall so fortuitously again and he was going to face a season chasing the Hamilton tail, all in the poisonous atmosphere that now sadly exists between the two. Or he could retire to Monaco with his young and growing family, more money than most of us could imagine and go down in history as an undefeated world champion.
What will he do now? I expect he’ll take a break but it would be great to see him in a sportscar sometime soon, where his consistency, speed and temperament would be ideally suited. The best sportscar teams are run like families in which team-mates work together towards a common goal. Completely anathema in Formula 1, it could be the kind of environment in which the talents of this still young, highly intelligent and personable racing driver are put to best use.