Game Theory - Why You SUCK at Card Games…

Episode Date: August 28, 2026

Most people SUCK at card games, but is there a way to guarantee a win every time? Well, in today’s episode we’re going to be breaking down the strategy so you can become the ultimate CCG player!

Two and five Canadians will hear the words you have cancer. That's why every step and dollar raised matters. On September 19th, join thousands in Toronto for the Princess Margaret Cancer Foundation Walk. Challenge yourself, friends, and family to walk 21 kilometers in support of life-saving research. Together, we can carry the fire and help create a world free from the fear of cancer. Register today at pmcfwalk.ca.ca. I suck at card games. Like, really, really suck.

But is there a way to actually be good, or am I just doomed by my bad luck? Hello, internet. Welcome to Game Theory of the Show that remembers when cards were for playing and not for collecting and selling on eBay. Kenneth Slavin, there's one bid. Okay, really? Already? Yes. Okay, hold on. What's the bid?

Six, seven, 20,000. Fortunately, we're actually bringing some of that childhood nostalgia back with a brand new show coming soon to TheoryVist. Are You Bored Yet? Where we will be playing tabletop games and card games like Magic the Gathering. But here's the thing. Santee and Lee didn't invite me to be in that episode. And it's all because I suck at card games. I know I made the joke earlier about cards being for playing and not collecting.

But as a kit, I did collect a bunch of them. And then I have no friends to play with. So you can imagine the childhood trauma that came rushing back when I found out that the friends I do now have didn't want to play with me. And I missed out on all of this exciting action. Okay. I'm only messing. I promise the show is way more fun than that clip makes it out to be. But of course, after this betrayal, the first thing I did was went back and watched Matt's video

that he did six years ago, where he broke down the math of card games to become a better player. But despite that, I've still been struggling. So, when our friends over at Marvel Step asked to sponsor a portion of today's video, I figured it was the perfect time to take Matt's video and go one step above. Where his video was Card Games 101, this is Card Games 201. We're going to break down the probability, psychology and decision making that separate a lucky player from a genuinely great one. So start ripping those packs, loyal theorists, because we're about to collect information on exactly what makes a... a CCG player, great.

As I mentioned before, Matt did a video on how to get better at card games several years ago. No, I will not be mentioning the number again. It makes me feel old. That video basically boils down to one thing. Math. When you're playing card games, you constantly need to be thinking about probabilities. If you're playing a card game with a normal deck of cards, probabilities remain the same no matter if you're playing GoFish or Blackjack.

Plus, there are plenty of books to teach you on how to count cards so you can become a poker pro in no time. But when you're playing card games like Pokemon, Yu-Gi-O, Magic, or Marvel Snap, things get a little weird. Each game lets you the player build your own deck, which means you get to essentially choose the probability of a certain card coming out of the deck. If you put four of your favorite cards in one deck, that means it's more likely to get pulled and so on. But to bring this card course up to the next level,

we need to dig way deeper into the psychology other than just player tells. Actual scientific theories that can, take us from a Weedle Wimp to a Pokemon master. And to do that, I want to talk about the Bayesian inference. This concept is actually vital to just being good at any card game. It combines two things that we gaming nerds love. Prior knowledge and data. At the core of this idea lies the Bayes theorem, which I'm going to show on screen right now.

At first glass, it looks pretty complicated, but it can be broken down in less mathy ways. Essentially, you start with a prior belief. Then you take into account new data. that new data makes you update your beliefs. It's honestly less of a statistical theorem and more like an advanced learning technique. All you have to do is apply that to playing card games. Think back to what I said about how in each set deck some cards are more likely to be pulled than others based on how many times they appear in the deck.

But as you pull cards, those probabilities updates and change. They don't stay static. So you now need to update your own mental data set. The longer the card game goes on, the more accurate your predictions become. For example, let's say you're playing Pokemon. Before the game, you'd want to study the current meta to know what is popular and what all the latest releases are. Typically, there are very popular decks within a current meta that a lot of players tend to use. Maybe you even know your opponent and already know what decks they're rocking with.

Whatever the case, that knowledge serves as your prior knowledge going into the game. Then, when their first card is played, that is your first hint. towards their deck that they're actually using. Picture this. You and your Pokeoponent have placed down your starter Pokemon cards. Then you flip over those starter cards and you see that your rival has flipped over a Charmander.

That means your opponent is now using a deck with a Charmander in it, which, yeah, sounds like a pretty obvious observation. But that means all popular decks that don't use Charmander are off the table. This narrows down their next potential move by a lot. The game progresses. They show more and more.

of their deck to you, which helps you update your perception. Are they going to be using a Charazard X Ente deck or a Charazard Y Maltre's deck? No, I don't have those cards. I never got them as a child. I know. Sorry, the illusion is broken. I don't have all the Pokemon cards. But eventually, you are going to be making very educated guesses on what their next move is.

Not because you have some special psychic ability, but because you're constantly incorporating new evidence and thinking one step ahead. hopefully beating your opponent at every turn and helping you bring home the victory. Once you have all of that probability stuff down, you can start jumping into psychology. This is what separates the statistician from the pro. Sure, you can play with fractions all you want, but being good at card games is more than that because, well, I can do math and I still suck at playing card games. So, one thing we can look at is signal detection theory.

Signal detection theory helps measure decisions made under uncertainty. Specifically, decisions with two possible choices. In normal situations, it would be easy to respond to a signal you're given. Either you see the signal or you don't. But maybe it's a foggy day. Maybe you can't see clearly, or there's heavy rain. That's where uncertainty comes in, which expands those two choices into four possible outcomes. You correctly respond to the signal, that's a hit.

You don't respond to the signal, but the signal is there, that's a miss. If you don't respond to the signal and the signal isn't there, that's a correct rejection. And finally, you respond to the signal and the signal isn't there. That's a false alarm. And just like with the Bayesian inference, signal detection might seem obvious at first, but it has a lot of real-world applications. Like, sure, all choices have consequences. That's just the reality of making choices.

But you can use it to analyze your personal decision-making. The theory itself was actually developed in the 1940s during World War II. Researchers were trying to better understand how radar technology worked. Those decisions whether or not to respond to a blip on the radar could be life or death. But sometimes those blips were just random noise. So signal detection theory was invented to help make those systems more accurate. And you can do it too to be better at Yu-Gi-Oh. Yeah, I'll probably seem a little small compared to World War II, but stay with me here.

Let's say you're playing Yu-Gi-O. Your opponent has thrown down a face-down, which could be the dreaded card, Mirror Force. No, I know this is not mirror force. It's the closest thing I have. I never got it because it's such a good and devastating card. It's hard to get. Two and five Canadians will hear the words, you have cancer. That's why every step and dollar raised matters.

On September 19th, join thousands in Toronto for the Princess Margaret Cancer Foundation walk. Challenge yourself, friends, and family to walk 21 kilometers in support of life-saving research. Together, we can carry the fire. and help create a world free from the fear of cancer. Register today at pmcf walk.ca.ca. Anyway, it is a card that when activated, reflects your attack and destroys all of the monsters on your side of the field.

It is a devastating card, and so signal detection theory shows us four outcomes. They have played mirror force down, and you don't attack, so you didn't over-extend, and you can now figure out how to safely attack later. They do have mirror force, but you attack anyway, which then wipes your side of the board.

They don't have mirror force and you attack correctly, identifying that it was a bluff and taking their life points, or they don't have mirror force, but you don't attack, meaning you've just kind of wasted your turn, and given the opponent more opportunity to gain the upper hand. This decision is obviously made so much harder because there are a lot of other things that affect the field. Are you attacking a monster in attack or defense position,

or are you just going for the life points directly? How many monsters would you lose if you guess this wrong? Are any of them particularly high value summons? There are also thousands upon thousands of trap cards, so it may not be mirror force, but it could be something more or less bad if it goes off. Additionally, there are other things that might play into the decision outside of just strategy.

Does your opponent have any tells? Are they looking too confident or are they upset with their first hand? If you're playing publicly, you might be distracted by the loud noise of the venue. If you're at home, maybe your dad walks in mid-play and asks, are you winning, son? All of these things play into the uncertainty of each decision you make, making the game harder than it already is. And in these questionable circumstances, you might lean towards making one decision or another

without even realizing it. If you do end up tracking your data, you might realize that you are more commonly putting out attack position cards, which means you have a liberal bias. If you're more commonly putting cards in defense position, you might have a conservative bias. Neither of these are bad per se, but you should try and change your decision making to optimize utility. Expert players aren't trying to eliminate mistakes entirely, but instead trying to choose the least costly option. And that actually ties into another decision-based theory that I want to talk about, prospect theory. And it's cool, you have to ask yourself a question.

Am I making the mathematically best decision or the more emotionally comfortable one? Yeah, we're getting therapists all up in here. The theory basically takes a deeper look at how people make decisions. It assumes that people really hate losing. They avoid losses like the plague, and their hatred for losing is actually stronger than their love of winning. This is also known as loss aversion, and in general, humans are less likely to take risks to make additional gain, but they are willing to take risks to avoid further losses. Even if the odds say otherwise, remember, card games are all about resource management and information is a resource. update your data and draw new conclusions.

Alter your decision-making to optimize utility. And don't be afraid to make uncomfortable decisions. Maybe now, Santee will invite me to his next magic game. But hey, that's just a theory. A game theory. Thank you. Two and five Canadians will hear the words, you have cancer.

That's why every step and dollar raised matters. On September 19th, join thousands in Toronto for the Princess Margaret Cancer Foundation Walk. Challenge yourself, friends, and family to walk 21 kilometers in support of life-saving research. Together, we can carry the fire and help create a world free from the fear of cancer. Register today at pmcfwalk.ca.ca. Thanks for watching.