Race to replace retired Rosberg keeps Mercedes high on the grid

Formula One heads into 2017 braced for change on and off the track.

Lewis Hamilton will again start as top dog at Mercedes and firm favorite to take his fourth world title, but after winning 19 of 21 races in 2016, starting all but one on pole and retaining both titles for the third year in a row, there is a good chance Mercedes will be less dominant.

For starters, the team will be without newly-crowned champion Nico Rosberg after the German's stunning retirement announcement only days after he won his first title.