Berzerkers of Khorne are (were?) noted for their close combat prowess. So, today I wanted to look at how many berzerkers it will take to kill a necron warrior in close combat. I am assuming that the berzerkers managed to charge and also got off a bolt pistol shot prior to charging.
The simplifying assumption here is how to deal with the necron's natural save of 4+ followed by the 5+ reanimation save. Combining them together grants the necron an effective save of 3+ (i.e. it saves half of all regular wounds, followed by ignoring one third of those that get through).
Let's resolve the bolt pistol shot first. It hits on 3+ and wounds on 4+. In other words a 0.33 chance of wounding. Using the effective save of 3+ (as above), the necron will suffer 0.11 wounds per shooting, charging Khorne berzerker.
When the berzerker makes close combat, he will have furious charge (assuming that this hasn't been denied to him thanks to the adaptive tactical genius that is Nemesor Zahndrekh). The berzerker attacks first and is hitting on 3+ and wounding on 3+. That means 0.44 wounds per attack. The berzerker has 4 attacks on the charge, which will lead to 1.76 wounds landing. Of these, the necron will fail to save 0.59.
Combining this melee result with the above shooting means that a singular, regular Khorne berzerker will cause 0.7 unsaved (and non-reanimated) wound when charging. Phew! I was worried that that would work out a lot worse!