Wombcat
Podium Finisher
Because not everything is the same on similar circuits.Then why didn't Rosberg walk away with it every weekend like he did in China? (Or at least on similar circuits).
I'm not saying I have the answers, but I think saying that it's just a matter of luck if the tyres work optimal on a certain circuit is a step too far (or several steps actually).
A team designs a car with certain characteristics. This car performs better in some arreas and worse in other areas than a competitors car. One of those areas may be how the car is able to heat up the tyres, to 'switch them on'. Heating them too much makes the tyres wear too much. Not heating them enough means less performance. Track tempature is a part of this. A team has to cope with all these variables. If Mercedes has a small window in which it is totally perfect, then that may mean that in those circumstances they have a significant advantage over other teams, who may be more comprimised to accomodate various circuits and temperatures.
I'm not saying that is the answer, but the team designs a car and they all get the same tyres. They have to find the best package in various circumstances. And that's the skill part. There may be a part of luck involved, but if it was just luck, then HRT would have gotten some points in the first races. They were steadily at the back, so it's not just luck, it's mostly skill. A small part is luck, but they still needed to design a car. At the first race it was already obvious that the Mercedes was fast in qualifying, but lacked in racespeed. In China they got it perfect. There's a small element of luck that at China the circumstances were perfect, but they still had to design a car that was fast in that operating window. Thye bottleneck of Mercedes may have been that their operating window for perfection was very small, but if they were not in their perfect operating window, they were significantly slower, so much that they were practically nowhere.
Apart from that it happens more often that a team has a good start of the season, but lack in development. Overall Mercedes were going backwards throughout the season. They were better in qualifying in the first half of the season than in the second half. The same goes for their racespeed.
And in Spa 2009 Force India got perfection. Don't think anybody called that "just luck" then.