what % of the time can you tell a fake from a real?

what % of the time can you tell a fake from a real? Because I've posted a lot of pictures on forums and they were authenticated wrongly. I know that everyone thinks they can smell a fake--and any fake--from a mile away, but is that really true?
 
"everyone" here definitely does not believe they can spot a fake.
I can't! LOL!
Actually I can if it's painfully obvious.
But the question about percentage. . . how can we answer that?? If we don't know it's fake and we think it is real. . . our perceived % would be wrong, no?
 
I'm actually pretty good with Coach and Louis Vuitton. I can't say my percentage is 100% but it is probably somewhere in the 90's with these brands. Usually hardware is a big giveaway or a style that you have never seen before. I will admit that there are good fakes out there. I wouldn't know a fake Kooba, Gryson, Botkier, or Prada though.
 
For me it depends on the brand..if it's OBVIOUS, then sure. But the only one that I am pretty good at spotting fakes for is Marc Jacobs, and that just came from learning from the experts over there.