Hearthstone is currently going through a bit of a rough patch. In Legend rank 40% of the players are using Shaman, every class capable of utilizing the 'pirate package' is doing so, and the rest of the decks are either a Reno variant or Dragon Priests. And to top it all off, Hunter and Paladin are in such a bad shape right now that they might as well not exist.
While all of this is pretty awful when it comes to Hearthstone's fun factor, it has managed to at least bring with it one blessing - Blizzard has finally started communicating! In his most recent Reddit post Hearthstone's Game Director Ben Brode has detailed how the team treats complexity and depth, as well as what exactly "design space" means for Hearthstone. The whole post is fairly short, so if you're interested in the design side of Hearthstone I fully recommend you give it a read. As for me, I would like to comment on Brode's thoughts on strategic depth:
"At any rate, making cards more complicated is easy. Making them Strategically Deep is more difficult. Making them simple and deep is the most challenging, and where I think we should be shooting. It's important to note that an individual design doesn't necessarily need to be 'deep' on its own.
Hearthstone has a lot of baked in complexity and depth: 'Do I Hero Power or play this card?' 'Do go for board control or pressure their hero?' And often (as in the case of Whirlwind) a card's depth exists because of how it is used in combination with other cards. Creating simple blocks that players can combine for greater strategic depth is one of the ways we try and get that high ratio of depth to complexity."
I generally agree with what Brode is saying here, but in my humble opinion it is exactly the lack of strategic depth that is currently holding Hearthstone back. The reason I say this is because the most powerful cards in the game right now are incredibly simple to use, and require absolutely no decision-making on the part of the player. Outside of avoiding AOE, can you think of any reason you wouldn't want to drop the Thing from Below, Small-time Buccaneer, Tunnel Trogg, or even Draconid Operative as soon as you can? And after you play those cards you are now committed to supported them with the obvious follow-up cards, and so the chain goes on. So instead of having to think about your options each and every turn, you can just as easily play the same strategy every single time and have a decent winrate, purely due to the power of these cards.
Playing overstated minions on curve is not strategically deep, and it certainly isn't interesting. As such, I would really love it if Blizzard could stop propping up archetypes with one ridiculously overpowered card, and instead move towards introducing a variety of simply 'OK' ones in order to let decks develop naturally. Reno Warlock is a great example of this as even though it carries the obviously overpowered cards the rest the deck is not chained to them, so you can get really creative with your choices in order to counter the meta. With Pirate Warrior this really isn't the case, and you're going to be basically playing the same game every single time, purely due to how effective and simple its 'plan' really is. So hopefully we're gong to see a bit more of the former, and a lot less of the latter!
If you've managed to survive all of that ranting, I do have one piece of good news to send you off on - Blizzard is currently keeping an eye on pirates, and is prepared to step in should they continue to be dominant!