As one of the "anecdotal statisticians" that originally circulated those odds, I feel obligated to confess that I've seen enough data since then to convince me that the actual odds are most-likely 1/8 x 1/8 (...which also makes more sense from a programming perspective, being a "binary exponent" and all).if you use the most commonly accepted (but definitely wrong to who-knows-what extent) rate of 1/7 to upgrade green>blue or blue>purp, then you're looking at 1/49 for green>blue>purp.
Even if there was... I can't imagine that it would cumulatively-track that across rerolled-characters!the numbers get more favorable if you believe there's some sort of safeguard mechanic built in that makes a proc more likely with each subsequent failure
As one of the "anecdotal statisticians" that originally circulated those odds, I feel obligated to confess that I've seen enough data since then to convince me that the actual odds are most-likely 1/8 x 1/8 (...which also makes more sense from a programming perspective, being a "binary exponent" and all)
Well, I have a theory based on elunifeimos's comment in https://www.wowhead.com/item=135539/crate-of-battlefield-goods . He says that, after opening 443 BG crates, he found that the chance of items upgrading to rare is about 1/8 (or 12,5%).
If you look at Blizzard's database, you will se that items from those crates are marked only as 'Chance to be Rare', which we can assume is equal to 1/8 (or 12,5%), while unique items are marked as both 'Chance to be Rare' and 'Chance to be Epic'.
I believe the chances of both events might be the same. So, if we want to calculate the chance of a green going epic we would calculate it in the following forms:
- 1/8 * 1/8; or
- 12,5% of 12,5%.
Solving by fraction or decimals we ended up with the supposed chance of 1/64 or 1,5625% of a green upgrading straight to epic. Keep in mind that there might be a system increasing the odds in favor of the player after each failed upgrade roll (or even item drop).
Rares to epic should still be about 1/8 or 12,5% chance if theory is correct.