Spoiler:
This is Incorrect. Avoidance doesn't work like that anymore. Go check the threads on it for the math breakdown, but basically it is just a roll now. If the attacker has 21 strikethrough(including int) and the defender has 50 disrupt, then a roll of 1-121 is made, on a roll of 1-50 the spell is disrupted, on 51-121 it is not. There is no difference anymore between gear and stat based disrupt. It is all calculated at the end the same, That is why they changed how DoTs are Avoided, because Avoidance suffered a Nerf(ish).
Edit: here's the math for you, as usual with these things, Thank Annaise16: viewtopic.php?f=8&t=23384