Board Thread:Questions and Answers/@comment-16190015-20140602051933/@comment-25968376-20151025221250

71.204.117.13 wrote: Did they REALLY upgrade feather's chance? I'm at 385k trying to get it to level 8, and this is a bit ridiculous at 15-20%... Sure, it could happen, but it's statistically unlikely to fail 11 times in a row at that percentage.

The statistical probability for getting it on the 10th try if the success rate is 15%, is 3.474% If the success rate is 10%, it's slightly higher, 3.874%. So while you're not terribly unlucky, it's not totally unexpected either. And I assume that the success rate is even lower for going +8 to +9.