by James Duggan on Nov 20, 2017
Ever since Hearthstone: Heroes of Warcraft was released in 2014, the competition to be the best in the world at the fantasy card game has intensified a great deal. What started out as yet another novel way to enjoy Warcraft characters and stories has become an incredibly popular format of its own.
Cover image: "Hearthstone Beta" (CC BY 2.0) by mrwynd
There are now more than 70 million players, and the game is often contested fiercely in professional tournaments such as the Hearthstone World Championship. The event pits 16 of the greatest players from around the globe against each other for a chance to win a share of a $1 million prize pool. To be able to play the game at this kind of level, players need to truly master it, and one way to become a top player is to become an expert of working out odds.
While mathematicians have spent years studying the ins and outs of odds in games like chess and poker in order to work out how to give themselves the best chance of winning, Hearthstone strategy is still rather young. One thing that all players will agree on is the fact that getting the right cards at the right time is important. For the purposes of this article, we will assume that those wanting to improve their games have already accumulated enough cards to put a powerful deck together. If you haven't done this yet, this is what you should do first. Rather than just buying packs for 100 gold to bulk up your deck, savvy players have worked out that it actually makes more sense to spend 150 gold for admission to the arena. At the end of your run you're guaranteed a pack anyway, and during the arena challenges you have a chance of winning gold, dust, and additional cards.
Because every single player is using their own unique deck in Hearthstone, each game is different and has to be taken on its own merits. This is one of the things that makes the game from Blizzard so unique and dynamic, but there are still elements of chance that come into play which are governed by odds. Knowing your own deck and the probability of drawing a particular card can help influence your decisions within the game and put you at an advantage.
Some dedicated players have done detailed research into the odds of drawing certain types of card on each turn. For instance, on turn 1, you have a 13.3% chance of a single legendary being reliable, and a 25.2% chance of a common, epic, or rare card being reliable. The chances of drawing any of these cards increases as each turn goes by, with there being a 75.8% chance of a common, epic, or rare card being reliable after turn 12. Another strategy of play is to have good early game, which means having a certain number of cards that cost 4 mana or less that you would like to keep in your hand against aggro. Say you have the ten recommended early game cards in your deck, the chances of getting two of those cards in your initial hand are 41%. If you choose to go higher than that and have 14 early game cards in your deck, your chances of drawing two in your starting hand are 65%.
Although players can construct their own decks based on their individual styles of play, there is still some luck involved with the game. In other words, players will know which of their cards they need in order to defeat their opponents, but they are still at the mercy of chance when it comes to that card peeling off the top of the deck.
By looking into other games that rely on odds, players may be able to improve their understanding of chance when playing Hearthstone. There are plenty of other games which are ruled by probability, which can help with players' grasp of the maths involved.
Odds and probability have been at the heart of games for years, with a number of other game genres using chance - in the form of RNGs, when it comes to video games - to make the experience more exciting. Hearthstone uses an RNG to make the drawing of cards completely fair, and because this system is 100 percent reliable, it has made it possible for players to work out the odds. There are plenty of other games that operate on this basis as well, such as Gwent, which is another fantasy card game. Solitaire and Hearts are other examples. The use of RNG is not limited to card games either - titles from all genres make use of them in one way or another. Slot machines, for instance, are one of the original games of probability, and have been in existence for over one hundred years. That suggests that players often like the unpredictability of games and the fact that they don't always know what is going to happen. In fact, slots are by far the most popular casino game, with 48% of respondents to a 2014 survey favouring the reel-spinning offerings. Slot machines, like most other virtual casino games, use a random number generator, which determines the outcome of each spin. This generator will decide where each reel stops, and whatever is shown on the pay line is what the player ends up with. Each reel has a certain number of stops with different symbols on, and if you have ten different stops on each reel in a three reel game, for example, the chances of landing a combination of those are 1/10 X 1/10 X 1/10, or in other words, 1/1000. In that same way, once you've got a constructed deck (or have chosen an arena deck) in Hearthstone, it's probability that defines when you'll get that all-important legendary that will help you beat your opponent, or whether you'll be able to play a card on turn 1.
Odds like this provide players with reassurance that the game is above board, and gambling authorities make sure that non-biased random number generators are used. These complex odds in slot machine games and the rules adhered to by random number generators all hark back to the old game of tossing a coin to see whether it lands on heads or tails. The odds of tossing a coin and it landing on either heads or tails are supposedly ½, so why do coin tosses sometimes lead to runs of one or the other? The best way to test the odds is to toss it over a large number of times, and the more times you do it, the more even the spread of results will be.
Other games like roulette, blackjack, and poker can be understood in this way, and regular players of these games have an ingrained knowledge of the odds when making certain bets. Poker and blackjack especially, have many similar elements to Hearthstone when it comes to probability.
A number of professional poker players such as Daniel Negreanu and Bertrand Grospellier have gotten into playing Hearthstone in recent years, so there is some truth in the fact that mastering other games which rely on odds can help your chances of winning. But possibly the best way to get a grasp of your odds is to play hundreds of Hearthstone games with the same deck, and really get used to the frequency with which cards get drawn. Keep track of your wins and losses, and learn from them.