After homebrewing about 300 batches of hoppy styles, I feel that I have gotten a pretty good handle on the game. Having said that, I would only have confidence with the 20% or so of the more popular varietals. Most of the time, I'll guess at least to one of their reasonable substitutions if not the actual hop used itself. And I have also noticed that I only have a reasonable opportunity to guess hops in beers that only use 2 or 3 varieties, max. More than that and they all blur together. And it also helps if the hops have been used in a dry-hop phase so that the aroma, flavor and bitterness can help to triangulate a particular character that relates to specific hops. Also, some hop varieties are more distinctive than others, and those are easier to guess. In other words, I feel like I can do this better than most folks, but I'm still not particularly good at it at all.