I was battling this guy on Showdown who used wide guard 3 times in a row and it always worked! It never failed! I'm pretty sure it's like using protect,that it's chance of failing rises by 50% after 1 use.So how did it work all 3 turns?
>Wide Guard can now be used consecutively without failing, although it still decreases the chance of success for Protect, Detect, Endure, King's Shield, and Spiky Shield.
As of Gen VI.
Hope I helped. :) Source