They didnt make it clear if or how BLP will build per spec (all of them at once, vs only when loot spec is set)Ok I checked my data from the last 3 weeks to get a VERY ROUGH estimate about how many KP is needed to get the next legendary (after having at least 2):
- about 10% of characters got the next legendary within the next 300 KP after last drop (sample size 27 of 286 chars)
- about 50% of characters got the next legendary within the next 600 KP after last drop (sample size 6 of 12 chars)
So I think this sample size is really not very good to make proper estimations and the KP weights are kinda outdated too, but for what it's worth, it shows that the BLP doesn't seem to start kick in until around 300 KP (similar value was seen in earlier statistics too), and the average KP needed for the next legendary is probably between 400-800 KP.
But the KP calculations are much more complicated than just calculating avg raid boss drop rates. I'd need to track more characters, re-calculate the KP weights and improve the whole tracking process to get better short-term estimates, but I haven't had time to do that yet. And if Blizzard is going to make separate BLP counter for each spec in 7.2 like the plan is, it's going to be even much harder to track these things then.
Higher difficulty gives more KP, it's all explained in the OP, but also all the KP values are currently outdated and not accurate because the drop rates change every month.
Lore said he'd get back with that... but he never did.