Chance of gathering HQ items - internal game mechanics

[eastwind]

This question is about how the game internally determines whether you get an HQ item on a given gathering attempt.

I can think of two ways of doing it: either using 2 RNG "rolls" or 1:

If node chances are 75% and 15% for HQ.

2 rolls: A RNG roll is compared vs 0.75 to see if you get anything. If yes, a 2nd roll is compared vs 0.15 to see if you get HQ. If you gather 100 times you get ~75 items, 64 NQ and 11 HQ.

1 Roll: If RNG roll is <= 0.15 you get HQ, else if it is <= 0.75 you get NQ. 100 tries should yield ~60 normal quality and 15 HQ.

My results seem to come closer to the 1 roll method. Has anyone heard a developer say? Has anyone has done extensive testing?

This matters if you need HQ items and you don't care about NQ item yield, e.g. for a class quest.

[Alx789]

The final probability will be the same.

[Suirieko]

15% chance means you're 15% likely to get an HQ, each time you hit it.

Even if you hit the 100% times, you're just as 15% likely getting HQ off the first strike as you are with getting HQ at the last strike.

[StouterTaru]

Easy enough to test in HW zones.

1. Find a node with Fortune +30%
2. Unequip gathering gear to get your success rate less than 30% higher than your HQ rate
3. Use Unearth II/Leaf Turn II
4. Gather NQ items