After running the LFR loot system and analyzing the results with unbiased scientific inquiry, I have discovered that the 1-100 roll you get is not, in fact, random! It is instead based on the following process:
1) Everyone starts with a baseline 10
2) Add the number of seconds you are AFK after the pull, but before the monster's death.
3) You used one ability more than any other, such as Flash of Light, Fireball, or Auto-Attack. Find the percent of your actions that this ability made up. For example, if you used nothing but Auto-Attack the entire fight, this is 100%. Multiply this percent by 35 and add it to your score.
4) Add the average alcohol percent of the last 3 things you've been drinking.
4a) Minus 10 if you took a "bio break" since you started (minimum zero).
4b) Add 25 if at least 2 of these drinks come from the list of: Red Bull, 5-Hour Energy, Monster, espresso, or that thing with all the foamed milk, and the espresso in the bottom, crap, what is it called? Dammit, what is it called? This is going to bug me all day. Sometimes it has cinnamon...
4c) Add another 10 for each of those three drinks that is a color not found in nature, such as fluorescent/neon orange.
5) If you pulled the boss, add the number of percentage points LOWER than the maximum health in the party you have. For example, if you are the tank with the party's highest health, add 0. On the other hand, if you are a 115k hp shaman in blue gear that runs in and facepulls before the 230k hp tank is ready, you have 50% of the party's max hp, so add 50.
5a) This bonus does not apply if the boss despawns after killing you. It only applies if the rest of the raid enters combat because of the pull.
6) Add 25 if you have the same item already.
6a) Add 50 instead if you have the same item from Normal or Heroic already.
6b) Double that bonus if it's equipped, but neither gemmed nor enchanted.
7) Add 25 for each vote-to-kick on you that fails because you are running with enough guildies to block the vote.
4d) Cappucino! That's it!
Find your total so far. Multiply it by the number of seconds you stood in "fire" before you died. For this purpose, "fire" refers to any location-based damaging effect with high graphic visibility and no desirable effects (which would exclude, for example, Goriana's Onslaught). If you did not die from standing in "fire", leave your score unmodified.
8a) After the multiple, add +25 if you blamed any healer on an open channel, such as /raid or /yell. Add +50 instead if it was in all caps.
8b) If you died in this way, got a battlerez, and died again the same way, the multiple increases to a flat x10 regardless of your lifespan either time.
9) Calculate this score for every raid member. Divide each person's score by the highest person's score to obtain a percent.
9a) "Highest person" does not refer to medical enhancement. It refers to the numerically largest value.
9b) Even if your score is 420.
10) Your result is now your 1-100 score. Remember to add your Role Bonus, which is always 100 when you are a DPS rolling on the tank weapon.