The 99% claim has popped up twice in recent days in the context of Chinese sports, and both times there are less than convincing arguments.
Firstly, a Shanghai Shenhua club lawyer told Sina in reference to Didier Drogba’s contested move to Galatasaray in Turkey:
“We now have evidence which we believe will give Shenhua a 99% chance of winning a lawsuit at FIFA.”
Unnamed legal sources tend to have a habit of exaggeration because they are anonymous –> untraceable –> unaccountable. But I’m pretty sure – 99% sure in fact – that Drogba’s own legal team would have made sure there is a water tight case for breach of contract by Shenhua (presumably for unpaid wages) before he moved to another club.