The newest Hearthstone expansion called The League of Explorers has landed, and the primary new mechanic in it is something called Discover. The ways these cards work is they give you 3 cards to choose from and you put the chosen one into your hand. As an example:
Now people seem to be modeling this ability off of the baseline 'Draw one card' ability and presuming that they are similar. I think that doing so is a mistake and seriously undervalues the power of Discover as a mechanic.
One of the things about Hearthstone is that hitting a really good curve and not missing drops is key to success. Drawing a card is helpful in that it gives you more choices but Discover lets you find a card that will fit your curve much more precisely. If you drop the Museum Curator above you can find the hole in your curve, or just look for a card that works really well against the particular matchup you are facing at the time.
If your hand happens to be loaded with cards that cost 4+ then drawing a card has a modest shot of giving you a good play on turn 3, but Discover is going to be a *lot* more effective at that. Also there are many cards that are strong but which are situational and Discover is good at letting you sometimes use those deadly silver bullets.
It isn't all good though. Combo decks almost certainly prefer raw card draw because they don't want random decent cards, they want to find their combo pieces. However, a midrange or control deck that mostly just wants value will love the selection that Discover grants, and it also doesn't deplete your deck if things do end up coming down to a fatigue war at the end.
My suspicion is that the Museum Curator above is never going to be a power card, but it strikes me as really good. It can kill 1 drops, be a speed bump, and help you find a card to fill in your curve. It means that you have something decent to do on turn 2 and many priest decks struggle with that.
There are lots of other cards with Discover and some of them are of course pretty weak, but I think people are really underselling the power of choice. One of the best examples of that choice is Dark Peddler.
Discover gives you the power of choice, and there are so many cards that are generally meh but situationally powerful that I think people will really come around on Discover once they start seeing it in action. If nothing else there will be tons of stories of people being in a losing situation and then Discovering the only card that can save them and those sorts of saves will stick in people's memories I think. That will take time though.
So there is my bet for League of Explorers. Discover cards will be underrated initially but will end up showing themselves to be powerful ways for good players to extricate themselves from bad situations. Choice is extremely important, and can make up for a lot of raw power.