# Question about corrupting gems

I am looking to corrupt level 20, 20% quality gems. What is most important is level 21. Of course the 23% quality would be useful but it's not as important.
What are the odds of getting a non-bricked level 21 gem from the double corrupting altar vs just using a vaal orb? In other words, which one has a higher chance to succeed in +1 level without ruining the gem. Ideally, I'd like to know the odds of: -level 21, 23% quality from double corrupting -level 21, 20% quality from double corrupting -level 21, 20% quality from vaal orb Last bumped on Aug 15, 2020, 2:24:52 PM
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" Hello there. Getting a lvl+1 from a vaal orb is 1/8 chance. Assuming a double corruption is the single corruption algorithm ran twice, it raises that probability, but raises the probability to get lvl-1 aswell. To get a 21/23, you would then have 1/8 chance on one roll (lvl21), and 1/10 on the other (qty23), resulting in an overall 1/80 chance. That's based on the theory that the second corruption behaves exactly like the first, of course. PLEASE QUOTE ME IF YOU ARE EXPECTING A REPLY
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" Great, thanks for the info, I've been wondering about this for a long time :) |

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