Master chests

[Ceuidear]

Hello everyone,
I got few questions about drops in chests:-

1. Does the looting chances of good items in chests vary from class of chests ?
Example:- Elite Golden Dragonscale chest is epic but drops Arcane shard but per how many chets is there a chance to loot the shard i.e. how many chests has to be opened to loot a shard??

2. Arena Master Chest is legendary & drops fossil so, is there a more chance of looting arcane fossil than a shard in Elite Golden Dragonscale Chest?

3. Has there been an increase in the chance of looting arcane fossil in Master Chests after expansion? (Asking this question bcoz i heard many people looting fossil in master chests soon after expansion)


Few days ago i poped up 115 master chests & looted just 4 vials which was so frustrating. So, later i decided to spam open more & now i have got 401 chests. Question is:-

1. Are there more chances of looting fossil or vial by spamming?
2. Are there any special ways to opening chests[ Like in a set of 5-10-20 ] ?

Gladly accepting all suggetions & tips
Thank you in advance.