The Secret to 12-0 in Arena – Analysis of Recent 12 Win Decks

The most interesting discovery I've made during the data examination was how different 12-0 decks were from all other 12 win decks. Take a look...


Hi! I’m Asmodeus, multiple times Legend and infinite arena player. I’m also the author of The Complete Guide for Hearthstone Player. I specialize in learning and improvement and today I’d like to share with you my analysis of recent 12 win arena decks.

I extracted and reviewed the data from post TGT decks submitted in 12 win decks thread on Liquid Hearth as well as my own 12 win decks from that period. I’ve also compared it with another analysis of 100 random 12 win arena decks to check for any statistical anomalies.  After confirming that everything is in order, I’ve been able to find out what are the characteristics of a 12 win deck and what’s the secret to going 12-0. Here is what we can learn.

What makes a 12 win deck

For every deck, I have listed the number of cards that belong to one of the five categories

  • removal (ie: big-game-hunter, fireball)
  • AoE/powerful swing cards (ie: elemental-destruction, mind-control-tech)
  • card draw (ie: cult-master, solemn-vigil)
  • healing (ie: earthen-ring-farseer, antique-healbot)
  • legendary (ie: Foe-reaper-4000, Ragnaros-the-firelord)

Let’s start with removal. The average 12 win deck will have more than 3 removal cards. Considering how difficult it is to get removal in arena, due to the majority of cards being simple minions, we can definitely see that prioritizing it in the draft is a good idea from the start. Most of the removal in the reviewed decks can also serve multiple purposes. For example starfire can be used to remove a minion, deal damage to the enemy or draw a card.

The average number of AoE or strong swing cards is 1.61. In this category there is significant variance. Some decks will have absolutely no AoE while others will get as many as 5.

Across all of the analyzed 12 win decks, the average number of draw cards is a little bit above 2 (2.21), but there is a very interesting trend in this category that I’m going to address when talking about 12-0 runs.

The number of healing cards is not surprising. At an average of 1.24 we can notice between 1 to 3 healing spells or minions in the majority of decks.

Legendary card statistics may be unexpected by some people. Less than 30% of the decks had any legendary cards. As you’ll find out in the next chapter, not that many decks get carried by powerful legendary cards.

Decks with large number of cards in one category will generally have less cards from all other categories, which naturally makes sense. If you have 3x flamestrike, 2x polymorph, 2x frostbolt and a fireball to top it off, you don’t really care for much draw or healing.

On the other hand, when you have a lot of healing and AoE you don’t need as much card draw and removal.

The types of 12 win decks

Knowing all the numbers, I’ve been able to divide the decks into three distinct categories:

1. Synergy decks

This type of a deck relies on powerful combinations of cards that are nearly impossible to defend for the enemy. Interestingly Druid is the easiest class to build this kind of a deck. A notable example was a deck that had multiple ways of spawning large numbers of small minions coupled with multiple copies of power-of-the-wild, savage-roar, force-of-nature and emperor-thaurissan!

A lot of people try to force their draft into a synergy based deck but only 4% of all 12 win runs were from this category. Thus you’re better off just building a solid deck, without being fixated on combos and synergies.

2. Powerhouse decks

The most obvious contender for a 12 win run. When people post an impressive draft, it will likely be from this category. At least one powerful legendary card and a strong core of top tier cards to support it. This type collects wins by brute force of threats that your enemy simply can’t deal with. Solid bodies with powerful effects which will let you run away with the game if you get a chance to play them.

22% of all 12 win decks can be described as a powerhouse deck, but what’s interesting only 11% of 12-0 decks belong to this category!

An example of a powerhouse deck in arena

3. Well-rounded decks

Finally the last category, decks which are simply solid. This type of a deck is the most common member in 12 win club. 74% of all 12 win decks are just strong and well-rounded combinations of common cards. A well-rounded deck will usually have a little bit of everything.  However it’s not necessary for a deck to include cards from all important categories to be considered well-rounded. What’s most important is the core of cards played on turns two, three and four. All of the data suggests that getting a free trade up on your enemy is the easiest way to set yourself up for victory.

Frequently Appearing Cards

The more decks I watched, the more clearly I could see cards that appeared over and over again. A plethora of argent-protector, knife-juggler, flame-juggler and cheap weapons like the stormforged-axe. What all of these cards have in common, is the ability to remove enemy minion without losing your own, for a very low mana cost. After you and your enemy put your 2-drops in play, the next person to use one of those “free trade enablers” will gain the control over the game. seal-of-champions and shattered-sun-cleric are just incredible for this purpose. Not only they stop your minion from dying during the trade, but they also buff it, so that it can kill even bigger minion next turn.

Due to early weapons (2-4 mana cost) being prevalent in 12 win decks another card that appeared often was bloodsail-raider. But it makes sense, it’s the exact same function in reverse order, you remove the enemy minion with your weapon and then play a buffed minion.

Next time you draft an arena deck pay special attention to those early/mid-game tempo cards that let you trade without losing your minions in the early turns of the game. They’re essential to getting a good score in arena.

12-0 vs 12-x

The most interesting discovery I’ve made during the data examination was how different 12-0 decks were from all other 12 win decks. Take a look at the chart below. It shows a comparison between 12-0 and 12-x decks in the average number of cards per category.

All of the values are higher for decks that actually scored losses along the way to 12 wins. More legendary cards, more removal, more healing and AoE and more powerful swing cards, yet the score is not as good. How come?

You may have noticed that one of the categories was not included on that chart. The average number of cards that let you draw from your deck.

The difference is pretty big. 12-0 decks have more than double the amount of card draw. Which means that even if you have less removal, less AoE and less healing, you’re still just as likely to get it because you’re drawing more cards. It makes the deck more consistent and while you can have a lot of great cards, sometimes you just don’t see them in a game and that may result in a loss to an inferior deck. Having more draw ensures that you’ll get to your strong cards and reduces the impact of unfortunate draws. This means that it’s harder for an enemy with a weaker deck to luck out and steal a win.

The Best Mana Curve

Other than the number of specific cards in each deck, I’ve also examined the average card cost of the decks. Surprisingly all decks were very close to each other in terms of the average card cost, which means that there is a right balance of cards you should aim for. We can also see that the 12-0 runs have slightly lower mana curve than the 12-x runs.

Your mana curve should peak around three and four mana, but the average cost is more important than the shape. Some decks are flat, some look like a mountain and others are flipping you off, the shape is mostly random. The average cost of a card in 12 win decks also tells us which turns in the game are the most influential on the outcome of any given match. Turns three and four seem to be extremely important and you should keep that in mind while drafting your deck.

What you can learn

You can take away a lot from all this data. First of all, we can see the general direction our deck should take. A consistent, early board control oriented deck. The most important turns in the game are turn three and four, and that’s where your mana curve should peak.

Prioritize removal and AoE cards over simple minions. Once you have all the important tools for your deck, you can pick card draw instead, to get them more consistently in your games. The slower your deck, the more you can benefit from healing and AoE.

Take the cards that enable free trades for you, such as argent-protector or shattered-sun-cleric.

Cheap weapons and efficient early removal are more impactful than big threats, because if you’re behind on the board from early and mid-game, you will die before your big minions can do anything.


This analysis confirmed some of my suspicions about the current state of the arena. I’ve been curious why I’m winning slightly more after TGT and it appears that my personal drafting tendencies happened to accidentally align with the direction Hearthstone arena went towards. More emphasis on the early to mid-game trades, more card draw and jumping on every piece of removal you can get.

With smart choices, you can build yourself a great deck without the need for legendary cards, although they clearly do help.

You can see examples of 12 win decks in the 12 win decks thread if you wan’t to take a look at them yourself.

Share your opinions and post your questions in the comments, I’m always happy to answer them.

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