The Value of Cards in Deckbuilding

Hey everybody, I’m back this week for a two part article to talk about the value of cards. No, I don’t mean what cards are worth in the monetary sense, but rather what cards are worth in deckbuilding and during in-game play. This week I’m going to be looking at the value of cards in deckbuilding and next week I’m going to be looking at the value of cards during in game play.

Value in Deckbuilding

Every card is worth just that, one card. When you’re building a deck, every card you add has both benefits and costs. There are certain cards like Dark Hole or Heavy Storm that have extremely obvious benefits with what seems like no downside to them. While the downside is often negligible when talking about powerful cards like those, they still have costs. For example, Dark Hole is great to clear an opposing field of 5 monsters, but by the same token you’re rarely ever going to want to trade it as a 1 for 1. Because of this, you’re rarely going to want to see Dark Hole in your first 6 cards. If your opponent goes first, they might summon a Thunder King or set a monster before passing. You’re not going to get the most out of your Dark Hole by 1 for 1ing it turn 1 with a Thunder King. You’d rather wait for them to summon a second monster and get a 2 for 1. This may seem extremely obvious, but you might be overlooking something. By having Dark Hole in your opening hand, you’ve slightly hurt your early game. Since you’re not going to trade it for a 1 for 1, it doesn’t do anything until they summon another monster. You’d much rather have Dark Hole as your 7th or 8th card in this situation so that you can get the most out of it, while still seeing a full 6 cards on your first turn.

To expand on that a bit, I’m going to give you another scenario. Let’s say you’ve opened Magician Shark and you’re going first. You open with the standard Shock lock, but you don’t have any traps. Instead you have a Dark Hole in your hand. In this situation, Dark Hole does nothing to ensure your win. We now have two drawbacks to Dark Hole; it slightly hurts your early game and it doesn’t do anything to ensure your win when you’re in a winning position. Are there any other downsides to Dark Hole? The answer is yes, but perhaps it is best demonstrated with a different card.

Let’s take a minute and look at Upstart Goblin. You give your opponent 1000 life points and you get to draw a card. Sure, there’s the obvious cost of giving your opponent 1000 life points, but is there more than that? What if Upstart Goblin simply read “Draw 1 card?” Does it have a cost? You’re essentially running 37 cards. The obvious answer is no. As soon as you draw it, it replaces itself giving you a slightly better chance of drawing whatever the best card in your deck is in that situation. Upstart however does have a cost. It costs 1 card. It is 1 card out of your 40. In order to add an Upstart Goblin to your deck, you had to give up the space of another card. Because the minimum number of cards you can run in your deck is 40, every card automatically has the cost of 1 card.  Because of this, you’re going to want to maximize your card choices. Let’s say you have a standard 40 card Rabbit deck. You want to add a Mirror Force to your deck. You have 1 of 2 options. You can either cut a card and add it or you can simply add it. Because every card costs 1 card, if you cut a card to add another card, you are forgoing all the costs and benefits of the card that you cut. Ideally, you should cut cards with higher costs and less benefits for cards with lower costs and higher benefits. This is the reason playtesting is important for deckbuilding. It helps you determine the costs and benefits of cards. When you add an Upstart Goblin to your deck to give you “39” instead of 40, you’re not just shaving a card off your deck, you’re forgoing the benefits of the other 40th card that you could have chosen to run instead.

On Running More than 40

This brings me to the other option you have when you want to add that Mirror Force to your deck. You could simply add it. It seems like the easy out to deckbuilding. I mean really, what’s the difference between 40 and 41? Well over the course of 1 game, it’s not much. Over the course of 100 games or 1000 games, it can add up.

Let’s say that you have couldn’t decide what to cut to add the Mirror Force so you just added it to your deck and you are now playing 41. Your opponent has a field of Glacia, Megalo, Pike. If your opponent can successfully attack you the next turn, you lose. In this situation, Dark Hole would be the best draw in your deck. Mirror Force certainly wouldn’t be a bad one, but it leaves you vulnerable to Marksman/MST. You’ve got 29 cards in your deck. That gives you a 3.448% chance of drawing Dark Hole.

If you haven’t seen the Hypergeometric Calculator, I highly suggest that you check it out here as it’s very useful.

Had you run 40 cards, you’d have 28 cards left in your deck instead of 29. This would give you a 3.571% chance of drawing Dark Hole. That’s a .123% difference in numbers. With only 1 draw, you have the same chance of drawing your best card in a 40 card deck as you do drawing your worst card in a 40 card deck. The same is true for a 41 card deck. But, by running a 40 card deck you increase your chances of drawing the best card by the .123% over your chances of drawing it in a 41 card deck. Had you run a 41 card deck, you’d decrease your chance of drawing your best card (the Dark Hole) in a given situation by the same amount that you’re increasing your chance of drawing your worst card (the 41st card) in a given situation.

The 41st card in your deck is always going to be the worst card. Just because you don’t know what the worst card is, doesn’t mean there isn’t one. By running more than 40, you’re accepting that you didn’t playtest enough and that your deck could be better. While .123% in that situation doesn’t seem like much, what happens when you’re in a similar situation 3 more times that tournament where you really need 1 card to stay in the game? What about when you take into account the decrease in the number of times you’ll open Rescue Rabbit in a tournament? In a 10 round tournament you’ll play between 20 and 30 games. In a 40 card deck the chances of opening Rabbit is 28.077%. In a 41 card deck the chances of opening Rabbit is 27.439%. That’s over half a percentage difference every game you play. Multiply that by the 25ish games you will play and you’ve got yourself a significant difference. If you went 7-3, what would have changed if you opened Rabbit in a game 3 where you didn’t open Rabbit? That could have easily been the difference between 7-3 and 8-2; topping or not topping.

You should all take away from this article that every card is worth at least 1 card. That in order to add a card to your deck, you have to cut a card and forgo its utility. Playtesting is important to determine which cards have the highest utility so that you can make the most efficient choices in deckbuilding. Also remember to not go over 40 cards. Otherwise you’re increasing the chance of drawing your worst card by the same amount that you’re decreasing your chance of drawing your best card in any given situation. Check back next week and I’ll have part two of this article dealing with the value of cards during in game play rather than in deckbuilding. Until next time, play hard or go home!

Patrick Hoban

Patrick Hoban

Patrick Hoban

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