Part 2: Card Analysis
Instead of reviewing every single card, I will take some prime examples from my Sheet, in order to illustrate what makes for a good pick and what doesn't.
Evolving Parasite kicks off my list and for good reason. Being able to kill any card is great, being able to copy any card is great, but what truely makes this card top of the top is its potential. Coming back to my premise that tempo forces bad trades: Evolving Parasite will force some really, really awkward blocking or scare your opponent into letting minor attacks through. Best yet, they may waste removal if you keep it in support or play into your mindgames. This makes for a huge card to play around, often going 3 for 1, wasting removal and stalling out a defense.
Splitter Robot is value incarnate. It's a strict 20/20 in stats, but being staggered and spread, it responds well to buffs and has remarkable resiliency against board wipes, kill spells etc. The tokens are useful for things such as chump blocking or powering Win Machine. In trades, Splitter will usually take 2 cards to take down, being the epitome of efficiency.
Following the same logic, the infected line of units has what is effectively Two Lives at a very competitive 3 cost. With both the Devil and Purifier geared towards offense, these guys will trade with their 3 drop peers and live. It is very hard to not go at least 1 for 1 with these. Being able to block two attackers regardless of their power is a big trait that has saved me more than once. The infected Monk has the added benefit of keeping buffs, meaning that after a few buffs with Daode or Support Drone, he becomes a big wall. His disadvantage is bouncing to the support zone, ranking him slightly lower in terms of defensive potential.
Harahel makes two 2/2 tokens, making him 10/10 for 4, slightly below curve. After ascension however, he gives 16/16 worth of stats plus some more. Pushing all of your minions beyond range of some common board clears, boosting their attack and flying past any blockers, he truely is an example of card worth and a board warping presence.
Two other cards that see massive use in Draft are Shikana and Bomb Bot. Being relatively easy to play around in constructed, these guys can kill an entire battlefield by themselves. What makes them stand out even more is the fact that you can retreat your own board at the same time. Shikana comes with a massive flying body, and the bomb bot can be grafted on your flyers if need be. Just like Parasite, the vast mind games these cards bring about can allow you to make small, unblocked attacks or provoke excessive responses. Their effects also trigger before anything else (resolution), meaning even a pre-emptive Suppress or Temporal Anomaly will fail to stop these guys. Simply put: with one of these two out, you control the board state.
What makes for a great card?
Great cards warp the field around them. They bring big stats to the table (Behemoth, Harahel, Splitter), threaten the opponent (Skraar's Young as someone eloquently put it: "Bullies other characters off the field"), make good trades (Parasite, Shikana) or bring about huge tempo swings. It is obvious why Splitter bot is such a good card. Nonetheless a card such as Consecration may seem inconspicuous but is both incredibly cheap, versatile and easy to draft. Being able to diminish an enemy board is just as important as building up your own.
Generally speaking, vanilla stats on curve will net:
1: 9 stats, generally as 5/4 or 4/4 with an ability
2: 14 stats, 7/7 being the benchmark or a sum of 12 with an ability
3: 17 stats, 8/9 being the benchmark, most cards offer 8/8 with an ability.
4: 22 stats, 10/12 being the optimal distribution, most cards offer 20 stats with an ability
5: 25 to 28 stats, with 12/14 being a popular one, most cards now deviate from total stats and instead have good abilites.
Big abilities are usually unique to a card or are the following traits: flying, bloodthirst, untouchable, charge, consume. These traits justify lower stats.
Small abilties are minor traits and usually don't interfere with stat distribution to a crippling amount: vigilance, unstoppable, immolate, reach.
If a card is significantly below curve, investigate its effect. Evolving Parasite is only 5/7 (12) worth of stats and doesn't pass the vanilla test. Nonetheless its effect is absurdly good, meaning it doesn't need to conform to these stats. Coyle Immovable is a 7/10 for 5, failing the vanilla test. Nonetheless it has vigilance and cannot take more than 3 damage from any source. In combat this effectively values him at 7/32+, being able to absorb 4 hits of his peers, each hitting for an average of 8-10 damage.
Look at stats for an indication of trade efficiency. Above mentioned cards will trade very effectively with their peers.
In short: a good card makes the battlefield revolve around itself. It is reliable, affordable and has either immediate effect or so much potential that it warps your opponent's play around it. Every card that made you say 'oh crap!' when you saw your opponent play it: that's a good card!
So what makes a bad card?
Bad cards fail to do the above or do so at an abysmal cost. Some 'bad' cards may see play in constructed, Best Fiends being a prime example, but they require certain synergies or tactics to work that are simply not viable in draft. Many Exile cards fail because of this, but every faction has some junk cards. Let's look into that.
The Hunter line of cards (bounty hunter, demon hunter, spec op) are 3 resource 6/8 humans. For comparison, 8/9 is the benchmark. Checking out their effect, they are both niche and restricted to a specific card type. Even worse, they will trade down for some 2 drops and will lose to pretty much all other 3 drops. The best they can do is break even and maybe go 1 for 1 with a 4 drop. This is not what you want in a card. For comparison, the infected line will also trade for most 4 drops but will not lose out to their peers. Upon further inspection, you will see that there is no reason to ever pick one of these cards over Infected Monk (stat equivalent) or any other 3 drop in the game.
Vandalize, Perils of Command and Rift to the Old World are also niche, but offer a neutral answer to Win Machine and Kyrallic. "What is so bad about that? Consecration is top tier!" The answer is versatility. Vandalize and Rift are both answer cards. Answer cards, such as spot-removal, are played under certain conditions and are otherwise dead weight in your hands. Almost all factions have answer cards to artifacts and locations, and theyre better than these. Consecration is cheaper (3 vs 6 cost), more versatile (targets both artifacts and locations), has a better effect (removal from game). It is mainly the expense that is vital: even if you destroy the Win Machine with a 6 cost Vandalize, he only spent 2 resources and you could not spend more resources on turn 6! In other words, you gave up playing something for only poking his board. This is a pit that Perils of Command falls into. Costing 5 mana, this card is both too slow and ends up being dead weight for most of the game.
An ideal answer swings games: tempo. This is why Corrupt Machinery is so good. It both kills their artifact and gives you the same artifact, being a strict 2 for 1. Being niche should be with great rewards, and Rift/Vandalize/Perils fail miserably.
Every card that you scoff at is a bad card. Cards that do not impact the board in a soonish fashion (Crystal/Chalice of Madness), that trade down (Hunters) or simply have strictly better equivalents (Vandalize) are awful.