A while ago I wrote a post with a lot of examples of pros making rather embarrassing mistakes in card evaluations for Constructed.
It's been a few sets since then, and examples keep coming four times a year.
The usual disclosures apply - I'm posting it to show that reviewing sets is hard, and you should take whatever people say with a grain of salt, not to mock anyone.
Fate Reforged - Gurmag AnglerConstructed: 0.5
Technically can be a one mana 5/5, but I think the other delve options are just better, even going back to cards like Hooting Mandrills.
Khans of Tarkir - Treasure CruiseConstructed: 2.0
I suspect Dig Through Time has made Treasure Cruise nearly obsolete, but Treasure Cruise is more splashable and is better raw card draw, so there’s a chance it sees some play.
Khans of Tarkir - Dig Through TimeConstructed: 2.5
I want this to be good and I’m going to spend a lot of time digging to make that happen, but it’s still an 8-mana spell to begin with. [...] It’s not quite Sphinx’s Revelation.
Magic 2015 - Aggressive MiningConstructed: 3.0
This is an aggressive rating for a very interesting card. I could see this seeing zero play, because it certainly is hard to utilize (and very dangerous when implemented incorrectly), but the card is just so powerful that I can’t help but imagine it being awesome in the right deck. One way to approach this is to play it as the top of the curve in a deck that really doesn’t need lands past three or four. Playing this on seven lands makes it close to a draw six, and that really isn’t that bad.
Born of the Gods - Brimaz, King of OreskosConstructed: 4.0 (the only such rating in the entire set)
Brimaz is going be the one king to rule them all, at least in terms of white beatdown decks. In Standard, he's going to be an auto-include in Plains-heavy aggressive decks, and is powerful enough to try many different builds of such decks. He's even purrfect for some different Modern decks, and it's funny that both Bitterblossom and Wild Nacatl could both potentially be paired with Brimaz to great success. The size, cost, and abilities all line up so well here that Brimaz is just impossible to ignore.
Journey Into Nyx - Mana ConfluenceConstructed: 5 (Fives are ever-present cards that heavily warp a format or see heavy play across multiple formats. Jace, the Mind Sculptor, Deathrite Shaman, and Tarmogoyf are good examples of fives.)
Many might not realize why this is so strong. It is because having perfect fixing for a three to five color deck found in a single land is worth some damage over the course of a game. Decks that play this will either have access to life gain, to offset the downside, or will be very proactive and aggressive, like combo decks, so that they don't care that they did three damage to themselves before killing you. This will be moderately played in Standard but heavily played in older formats wherever City of Brass has popped up in the past.