Any 10 vs 25 man bull will be auto infracted. This is about gear, not difficulty. Only warning, you post about it, should have read. ~Myrrar

Since there's been a lot of talk lately about 'strict' 10 man raids and how their rate of gear acquisition compares to 25 mans, I wanted to see how exactly they compare. Specifically, the common argument from the 10 man raider side is that loot is more likely to be actually useful for someone in the raid in 25 mans than it is in 10 mans, so 10 man guilds will gear up more slowly even though the loot dropped per player is pretty similar between the two raid sizes.

To do this I simulated loot drops for 10,000 raids in both 10 and 25 man until every player received every piece of loot they needed. Along the way I tracked a couple points of data for comparison: Average, minimum, and maximum number of runs needed to gear up 50%, 75%, and 100% of the raid.

At this point I will say that these simulations did not take into account the actual boss loot tables from Firelands, or any existing raid. The goal here was not to get a perfect picture of how raids can gear up in Firelands. I'm more interested in the general concept that RNG is more noticeable in 10 mans than it is in 25 mans, so I made some assumptions that don't accurately reflect actual boss tables, with the hope that the simulator will still be close enough to get an idea of the difference in RNG. The notable assumptions/simplifications I made were:

1. Only consider the 8 armor slots, meaning helm, shoulders, chest, bracers, gloves, belt, legs, and boots. For now I'm not worrying about weapons, trinkets, jewelery slots, etc. I'll probably go back and add these slots in later, but again I'm not looking for realism, just an idea of how RNG affects 10 mans and 25 mans.

2. Assume that exactly 1 piece of gear for each armor type drops for each slot and is BiS for all specs that use that armor type. Again this isn't how boss loot tables in Firelands actually work. For example, most armor types have only 6 drops in Firelands, with cloth having 7 and leather/mail agility having 5 each. This is also ignoring tier tokens, BiS valor point items, etc. I will probably work tier tokens into the simulator eventually, but the rest I'll probably leave alone since the specifics change from tier to tier.

3. Assume that there are 8 armor types: Cloth, Leather Agility, Leather Intellect, Mail Agility, Mail Intellect, Plate Strength Dps, Plate Strength Tanking, and Plate Intellect. It's a little risky to lump all Cloth into one category, but since there's 0 cloth spirit drops in Firelands this should roughly match how loot is actually distributed in game.

4. Assume 8 bosses in the raid. I'm not sure how changing the number of bosses will affect the outcome and 8 is a pretty reasonable count, so I used it because it makes the math much easier.

5. Assume that drops are determined by 2/6 randomized, independent rolls where each piece of gear has the same chance to drop on each roll. I believe that this isnotan exact representation of how loot is dropped in game, but it should be close enough.

6. Assume that class distribution is as close to optimal as possible. This means that 10 mans have 6 armor types covered by 1 player and 2 armor types covered by 2 players. For example, they might have 1 player on each of leather agility, leather intellect, mail agility, mail intellect, plate strength dps, and plate intellect, and 2 players each on cloth and plate strength tanking gear. 25 mans have 7 armor types covered by 3 players and the 8th armor type with 4 players. This is something I want to play around with in the future since another argument of 10 man players is that it's harder for them to run a perfect raid comp.

7. Assume hard mode drop rates, so 2 drops in 10 man and 6 in 25 man.

8. You raid with exactly the same people every week. No 13 man rosters for 10 man raids or 35 man rosters for 25 man raids, you gear up exactly 10/25 people. This is something I'm not likely to change since it seems like a lot of work for little benefit, so just keep it in mind.

With that out of the way, here are the numbers I came up with after 10,000 simulations. On average it took 10 mans 3.75 runs to get 50% loot saturation, 6.78 runs to get 75% loot saturation, and 21.82 runs to get 100% loot saturation. For 25 mans the numbers were 3.00 runs for 50%, 4.12 runs for 75% saturation, and 11.85 runs for 100% saturation. The other notable differences were that the worst case scenario for 75% loot saturation on 10 mans was 10 runs compared to 5 runs for 25 mans, and the worst case for 100% loot saturation was 25 runs for 25 mans and a whopping 52 runs for the 10 mans.

Keep in mind that the numbers only account for 8 slots out of ~16 per class, so in reality you won't gear up this quickly. What's more important is the ratios between the two sizes. You can see that early on the difference is small, since when you don't have much gear there's a good chance that any drops will be useful. It takes about 25% more runs for the 10 mans to reach 50% loot saturation than 25 mans, so keeping in mind that 25 mans drop 20% more loot per player (6/25 compared to 2/10) the RNG factor is almost non-existent. At 75% saturation it took 64% longer for the 10 mans than the 25 mans, so the RNG is pretty noticeable at this point. For a full 100% saturation it took 10 mans 84% longer, almost twice as long, as it did for 25 mans. And the worst case scenario took more than double the number of runs for 10 mans than the worst case scenario for 25 mans, a whole 52 weeks, or in other words a full calendar year.

Some things to keep in mind about the assumptions made earlier:

1. Any BiS gear that is obtained outside of raids, such as casters using Darkmoon Card: Volcano, items such as relics or wands bought with VP, BiS crafted items, etc. will reduce the gap between the raid sizes. This is because there's no difference in gearing rate outside of raids between 10 man and 25 man raiders.

2. When the raid is fully/mostly decked out in drops it's much easier to gear up a fresh recruit in 25 mans than in 10 mans.

3. 10 man raids have much less granularity when it comes to raid composition. Consider a raid with a mage, warlock, shadow priest, disc priest, rogue, boomkin, hunter, holy paladin, prot paladin, and prot warrior. This is a completely reasonable raid comp that covers most raid buffs and only overlaps 2 classes with 2 players, but the gear distribution is much worse. You have 2 armor types with no users and cloth with 4 users. A 25 man almost has to purposely try to build a raid with a loot distribution that unbalanced.

So, what does this all mean? Well, early in a new tier raids of both sizes are likely to put most of their new drops to use. As the raid continues to farm gear it's more likely that players in the 10 man will be left with empty slots while 25 mans can reasonably expect to have all of their players close to BiS. So when the new raid comes out the 10 man will probably have a slightly lower average gear level going in than the 25 man, with the gap quickly shrinking for the first few weeks and then growing again as the raid is farmed over and over, until the next raid comes out and the process repeats.

Edit: Alright, finally got it working with a much more realistic setup. The simulator was improved in a couple ways:

1. All item slots are now covered, including tier pieces. For tier slots I assumed that every player would want 4 piece + 1 off-set. The off-set piece is randomized for each player.

2. Raids are now randomly generated. All raids must conform to a set of guidelines, such as 2 tanks, 2-3 healers, etc.

3. I now assume 10 bosses per raid that have 13 unique pieces of loot, plus tier tokens on 5 of the bosses.

The results, as an average of the number of runs needed for the given level of loot saturation:

50% loot saturation

10 man: 7.10 runs

25 man: 4.87 runs

75% loot saturation

10 man: 13.26 runs

25 man: 8.48 runs

95% loot saturation

10 man: 30.33 runs

25 man: 17.65 runs

Numbers are up across the board of course since there are a lot more gear slots to fill out. The ratio between the time to gear up starts higher but doesn't grow as quickly compared to my first simulation. The 10 mans now take 46% longer to reach 50% saturation, 56% longer to reach 75% saturation, and 72% longer to reach 95% saturation. The first sim showed the 10 man taking 84% longer to reach full saturation, so the story looks a little better for 10 mans now.