I think it is very important to keep in mind that it is not very relevant to judge if someone is good at predicting stuff simply by dividing all the predictions made by the ones that turned out to be correct.

I predict that tomorrow will by Friday. Given that today it is Thursday, that's not so impressive. So my point is that it is more important to look at how difficult to make was that prediction and what the reasoning behind it is.

And I would also look and see if I can find improvements in the predictions that are made, if the person making the predictions actually learns something from the mistakes that he/she made in the past and applies the things that are learned to the new predictions he/she makes from that point on.