Originally Posted by

**syrant**
Hopefully this post is informative since Thunderforge is such a heavily discussed topic on these boards. I'll try to keep to the stats.

I wanted to answer how much TF items affect ilvl differences between 10/25m raids.

How I modeled/Assumptions:

Item lvl calculation as average of 14 equipment slots

Starting item level of 500 (all raid members have 14 500 ilvl items)

Each 10m boss drops 2 items, 25m drops 6 items

Respectively 10% and 25% TF drop rate (using wowprogress.com research)

No wasted drops, completely efficient (each 522 replaces a 500, each TF replaces a 522 if there are no 500)

Unaccounted: tier drops, valor items, bonus rolls, drop distribution efficiency

You can find the google doc spreadsheet for this here:

edit: Don't have privilege

Results:

Comparing a 10m guild vs a 25m guild with the same number of boss kills:

Every 12 boss kills will result in a ~**0.96** item level gain for the 25m to the maxima of ~**4.4 ilvl at 55 boss kills**

At that point, the ilvl difference will rapidly shrink with more kills to minima of ~1.2 item level

From then on, every 12 kills will result in a ~**0.2** item level gain for the 25m to a maxima of ~**4.0 ilvl at 230 boss kills**

After that, the ilvl difference will slowly dwindle to 0

This can probably be understood in phases:

phase 1: 25m gears up much faster than 10m at the start mainly because of higher item drop rate, maxes when everyone in 25m is 522+ geared vs some 500 items in 10m

phase 2: 10m decreases gap when it replaces out remaining 500 items

phase 3: 25m higher TF rate allows it to more quickly get everyone to 528 ilvl, increases gap

phase 4: 25m is all at 528, 10m decreases gap with each TF drop

Conclusions (from model):

25m will be 1-4 ilvl higher than 10m throughout the tier

Item lvl advantage is picked up largely from higher drop rate (6/25 vs 2/10, which is a 20% more)

TF items represent a long-term source of item level difference between raid sizes, but much less than drop rate

I would like to hear if there's anything major that I forgot to include within model. There are some mitigating and aggravating factors to the ilvl difference that is unmodeled (listed above) and that I judged wouldn't greatly change the end numbers.

tl;dr: 25m and 10m ilvl gap at the start of the tier is roughly the same (max of 4-5 ilvl). Before, 10m would then close gap to 0. Now, gap will remain and slowly increase over the course of the tier (from 1 to 4 ilvl).