Rosberg needs to start out qualifying Lewis. OK, it's not an easy task, but that's where his main problem lies - which ever Mercedes wins the first corner will probably win the race, and starting from P1 gives you the best chance. Also IMO, Rosberg appears to lack that killer instinct when hunting Lewis down, something I believe Hamilton does have. Would the result have been the same if it had been Senna, Schumacher or Alonso (Vettel as well) doing the hunting in the final few laps of Bahrain and Barcelona? Who knows, but I can't help feeling the result may have been different.