Posted by david b. on October 18, 2014

*Elie Bursztein now looks into the attributes for each card in Hearthstone, providing a few simple examples of value discrepancy for some of the common ones.*

Another assumption is: the power of the cards roughly increases linearly, which means a 2-mana card is roughly twice as powerful as a 1-mana card. If this hypothesis were not true, some players would have no chance of success. So, roughly, the linear is something you need to be able to have the game balance between short-term and long-term. It’s not quite linear, but it’s a reasonable assumption.

Finding good synergy between cards is one of the fun aspects of the game.

Card effects have a constant price. It means that the Divine Shield or any effect has the same price regardless of the card it’s in. So there is no discount for specific cards, there is no secret, which brings us to the fourth assumption: having a card has value. Remember, you only get one card each turn, so even holding a card has some value, which we call the intrinsic value of the card. And finally, we believe there is no secret. We believe Blizzard has no hidden component, hidden balancing factor, and what you have in the card is exactly what the value of the card should be. So if you sum all the attributes, you will get the value of the card. How you sum them is another question we are going to explore, but there is nothing secret about it, and we believe everything is in the game and you can actually look at it. That’s where we start.

So, how do we model a card? Well, as I said, the mana is the price, and the price is equal to the attack and the health and the intrinsic value of my YetiA giant fireball is called the Pyroblast – bigger, stronger, meaner. The Pyroblast is 10 mana, and for 10 mana you get 10 damage. Well, okay, but then in that case it might be bigger but the value is not that great. You get 1 mana – 1 damage, and you can immediately see that’s not quite right. If you have 10 mana, you can play 2 Fireball and a half for the price of 1 Pyroblast. So the value of the Pyroblast is less interesting than that of the Fireball. What’s interesting is this is a new version of the Pyroblast. Earlier this year, we had a “pre nerf” version which used to cost 8 mana, where at that time the mana cost was even lower than the Fireball. Basically, before the adjusted value we get 1.25 damage for 1 mana. So, something is not right here, is it?

Let’s compare the twoSo there’s an imbalance. Even if you look at simple coefficients, you can see that there are some decisions which you can debate. Of course we don’t have all the data that Blizzard has, and it’s probably based on statistical analysis. But there’s some sort of mismatching complexity that is the basic, core idea of finding undervalued cards.

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