Originally Posted by
Dracodraco
While it's an interesting read, the issue here is that you're not distinguishing between 10 and 25 man's. Back in ICC, 10 man normal was equivelant to what LFR is today - the easiest game mode, could be done with most pugs, dropped the lowest Ilvl loot, etc, etc.
This means that it was pugged, and thus tons of guilds would have killed the encounter, and alot of them with mains from more established 25 man guilds to carry them through it (because 10 man didn't lock 25 man).
So you taking the numbers of guilds that's killed 10 man marrowgar is severely skewered, simply because of PuG's creditting more than one guild at a time.
That all changed with T11 and 12, which really should be included in your statistics, at the very least because you'd see that the participation amount in T11 was far bigger than T13 - 71K guilds killing the first boss, and 50K finishing the tier.
The reason for the drop in Dragon Soul normal mode participation can be accounted to a diminishing amount of raiders (84K->71K->64K->55K), but also to the fact that the DS normal modes were tuned to be slightly harder on the gear checks than any previous normal modes were, because LFR is / was supposed to change normal mode from "what everyone does when they're bored and have a little extra time, requiring no organization and no set raid schedule". Effectively adding a third difficulty mode that shaved away the bottom percentages of players, because the normal modes became harder.
Also, wowprogress stops tracking kills when a new tier is released.