Battles for the drivers' championship define seasons. What the Bahrain Grand Prix offered us, as well as one of the best Formula 1 races of the 21st century, was the first genuine shooting war in the tantalising head to head between Nico Rosberg and Lewis Hamilton.
On track, Rosberg was the aggressor, but off it, it was Hamilton who was on the front foot. During the weekend, he wasted no opportunity to highlight the unseen battleground that will prove a deciding factor in which of the pair prevails.
In Malaysia a week earlier, Hamilton was superior on all fronts. Faster, wiser, more fuel efficient, stronger on tyre management. Rosberg didn't have the ammunition to take him on and had to settle for second. So what had changed in Bahrain? On Saturday evening, Hamilton took his first gentle dig at his team-mate.