Thank you for starting this thread. I came to the forum to try and figure out what I might have been doing wrong with this quest.
Due to unforeseen personal issues I was forced to take a break from the game from just after MoP launched, and only recently came back, shortly before the launch of 5.2. Despite having cleared T14 for the last 4 (four) weeks on LFR (OK, missed one wing of HoF one week), I am now at 7 Power and 15 Wisdom. Don't believe I even got a single Power this week...
If I am very lucky, then I might only need another two weeks to get the remaining sigils I need. This seems like a brutal nerf to 'reward' returning customers, considering it apparently took 2-3 weeks to complete this before the nerf if you cleared all of T14 every week.
The truly sad thing is, that judging from some of his recent comments/tweets, then at least Mr. Ghostcrawler himself seem aware of the fundamental problem: Having players collect 'compulsory' quest items decided via RNG and a fixed drop chance.
(Sorry, light math follows...)
Say the drop rate for a Sigil from MV is 15% (not sure?), and half of those will be Wisdom. So the - average - chance to get a Power is 7.5% per boss kill. The question we can now ask is this: How long will it take for a player to collect 10 Power? The perhaps surprising answer is that there is never any guarantee any given player will ever be able to complete this quest, or any quest similar to it.
Worse still, it is a statistical certainty, that in a large player population many people will struggle for a very, very long time without being able to collect the required items.
Imagine we just need to collect one item at a drop rate of 7.5%, and that 1 million players attempt to get it. So the chance of *not* getting the item on any given kill is (100-7.5)% = 92.5%. Let us try to calculate the chance that a given player will not see even *one* item after X 'weekly first' boss kills:
For the first kill the chance is 0.925 (92.5%).
For two kills the chance is 0.925 * 0.925 ~ 0.8556. It didn't drop on the first attempt, neither on the second.
In general, the chance of *not* getting the item after X attempts is:
Chance as fraction = (1-p)^X
where p is the chance of seeing the item drop, also as a fraction, X is the number of attempts and ^ is the 'power of' operator: 2^3 = 2 * 2 * 2 = 8.
So what is the chance of not seeing even one item after, say, 4 weeks of clearing MV after the nerf? We have 6 potential drop chances per week, so X is 24: (1-0.075)^24 = 0.154 = 15.4%.
If we had the 7.5% drop chance when 5.0 launched (and assuming this is what it now is) and we imagine 1 million hopeful players started the legendary questline, then
0.154 * 1´000´000 = 154´000
players wouldn't have seen even one Sigil of Power drop after 4 weeks of clearing MV !
And we need 10 of them...
This is perhaps a stunning result, and shows just how useless the simple system of a flat drop chance is in a situation, when players *has* to collect a fixed number of items or be stuck forever. The numbers for drop chances I used above may be off, and the devs are the only people with the right figures. But the conclusion stands, regardless of the actual figure. The same system they are implementing in 5.3 for bonus loot rolls must apply to any 'compulsory' quest drops: Eventually the drop chance must be 100.0%, a guaranteed drop after X kills/rolls/whatever.
The alternative is the situation we now have, where some people are done in a few weeks, yet with a sufficiently large player base we will have many thousands of deeply unhappy players, who will quite literally never complete this hurdle.
This is not an issue of personal determination, player skill or just 'sticking with it'. This is flawed Statistics 101 understanding on part of the developers. I have heard an excuse had been made that this is a database resource issue, and that tracking details like these across the whole player base would be prohibitively resource intensive.
I sincerely hope this is a misunderstanding, because firstly we now get the 'increasing probability' mechanism in 5.3 for the bonus loot rolls. And secondly, many much smaller game developers are able to track much more complex data for each of their players. The best such example I am aware of is probably found in EvE Online, made by Icelandic game developer CCP Games.