Quite simply, the class that will be most affected by the changes in the current Standard format will be Warrior. Majority of the popular changed Discover cards are either Warrior class cards or are commonly seen in Warrior. The class that dodged severe nerfs last patch, with only Dr. Boom, Mad Genius getting his mana cost upped (which obviously mattered, but didn’t change the deck’s power as much as a lot of players would want) is now getting indirectly nerfed. Coincidence?
Let’s start with the most important one – Discovering Mechs. It’s a big part of the current Control Warrior’s power and possibly the main reason why players hate the “Created By” meta. Warriors have two ways to discover Mechs – Omega Assembly, as well as Dr. Boom’s Hero Power Delivery Drone. Pool of Mechs is actually quite big, but the truth is that a lot of the Neutral ones are simply bad or at least not impactful enough at the time you use your Discover effects (late game). Faithful Lumi, Mecharoo, Skaterbot, Galvanizer, Spark Engine, Unpowered Mauler, Alarm-o-Bot, Demolisher or Spring Rocket are great examples of minions that you don’t really want to get in the late game. Even among the higher cost Mechs, there are a bunch of cards that are “meh” or straight up bad – e.g. Spark Drill or Unpowered Steambot. Roughly 1/3 of Neutral Mechs could be considered “good” picks, even less of them are really “premium” cards that you really want to get (~1/5). On the other hand, let’s look at the Warrior class Mechs. Eternium Rover, Vicious Scraphound, Clockwork Goblin, Omega Devastator, Dyn-o-matic, Security Rover, Beryllium Nullifier, Tomb Warden and The Boom Reaver. Out of those nine Mechs, only the two first are not great in the late game – and even they are significantly better than their Neutral counterparts (plus gaining Armor is pretty important in some matchups, so you might end up picking them over other theoretically better options from time to time). That’s 7 out of 9 great picks (and 3-4 of those are absolute premium picks), a ratio significantly higher than among Neutral cards.
Before the changes, a chance to discover any specific Class Mech used to be 16.29%. After the changes, the chance will be the same as discovering any other Mech in the game and will go down to 6.67%. It means that we should see ~2.44 times less Warrior Mechs discovered on average. To put it simply, situations in which your opponent got fourth or fifth Omega Devastator should now be significantly less common. It might not seem like much, but this is a big hit to both Omega Assembly as well as Dr. Boom, which drew much of its power in slower matchups from discovering powerful Mechs.
But that’s not everything. Another card affected by the changes also belongs to Warrior – Frightened Flunky. Once again, a pool of Taunt cards is vast and they vary in power level heavily. However, if we look at the pool of Warrior class Taunts, we have – you guessed it – only good picks: Frightened Flunky, Armagedillo and Tomb Warden. I’ve played Control Warrior in Saviors of Uldum and I have to say that getting another Armagedillo or Tomb Warden often won me the match. Even getting another Flunky is extra body for free in slower matchup as well as a chance to re-roll. Now Flunky will be way less consistent, maybe even to the point of removing him from the deck. With Flunky gone, there’s a chance that the entire Taunt package will have to go. Alternatively, players might not make any changes, but in either case, power level of the deck will go down.
And last, but not least, another card affected by the nerfs is actually Archivist Elysiana. While it doesn’t work like a regular Discover card (putting whatever you pick into your hand), it follows the same rules – class cards were still weighed at 400%, meaning that you (in this case) used to get Warrior cards more often than neutrals. Given that, just like I’ve mentioned already, class cards are on average stronger than neutrals, you often preferred them. If you could pick only from class cards instead of neutrals, you’d gladly do it. After the patch, an average deck created with Elysiana will contain less class cards, meaning that it will be slightly weaker. Of course, you always ended up with a bunch of weird and not necessarily useful cards after playing Elysiana, but now you will have more of those on average. Considering that Elysiana herself is neutral, it’s not a direct nerf to the Warrior, but the truth is that Warrior is the class that uses her far more often than any other. The only other build using Elysiana right now is Control Shaman, which is an off-meta deck (<0.5% popularity compared to the Control Warrior’s ~6%).
On the flip side of this, the changes have actually had a buffing effect on Rogue and Mage…
Heistbaron Togwaggle (or more specifically one of its treasures – Zarog’s Crown – Togwaggle actually DOES see some play, and Zarog’s Crown is a commonly picked treasure, so the changes will make an impact here. However, it’s one of those rare cases in which new Discover weighing will actually be a buff. Given that summoning does not trigger Battlecries or Combos, Rogue Legendaries are usually much worse to pick than Neutral ones. Edwin VanCleef, Face Collector and Gral, the Shark are vanilla 2/2’s. Myra Rotspring and Captain Hooktusk are also way below average. Even the higher stat ones are either 5/5’s (Heistbaron Togwaggle, Anka, the Buried) or 6/6’s (Tess Greymane, Tak Nozwhisker), which is still only an average outcome. It’s one of the rare cases in which picking a Neutral card is preferable most of the times.
Power of Creation – Just like in case of Togwaggle, this one is actually a buff to the card. Right now, Mage has four different 6 mana minions in Standard – Arcanosaur, Meteorologist, Reno the Relicologist and Toki, Time-Tinker. The former two are literally the worst minions you can roll, while the latter two are pretty average outcomes. The fact that they are offered more commonly makes getting premium Neutral options such as Damaged Stegotron, Boulderfist Ogre, Sunwalker or Cairne Bloodhoof less likely. It also made picking Power of Creation from Tortollan Pilgrim significantly worse, because you couldn’t even pick so you often got the worst option. It would matter much more if Highlander Mage wasn’t nerfed in the last patch, but hey, the card is still playable and will remain in Standard all the way until 2021, so it’s a significant change.
All in all, I think this change is very cleverly done by Blizzard
