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Brewer's Minute: Opportunity Cost in Deck Building

Hey, everyone! It's time for another Brewer's Minute. One question I get all the time is, "Can card Y work in deck Z?" In a broad sense, the answer is almost always yes—in theory, it can work as long as you have the right colors of mana to cast a card. However, this is the wrong question to ask. Instead of asking "Can this card work?" a better question is, "What's the opportunity cost of playing card Y in deck Z?" If you're not familiar with opportunity cost, it's an economic term that means "the loss of potential gain from other alternatives when one alternative is chosen." So today, we're going to talk a bit about how opportunity costs influences the cards we put in our decks with the help of a couple of examples. By learning to ask ourselves the right questions during our deck-building process, we'll end up with better decks in the end!

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In Magic, the number of slots we have for cards in our deck is a finite resource. When you consider that a typical Magic deck has somewhere between 20 and 25 lands, this means we only have maybe 37 slots for non-land cards in our main deck. As such, each slot is precious. With 15,000 cards fighting for these slots, there's a huge opportunity cost to playing one card over another. With so many options available, the challenge of building a deck is trying to figure out the best option for each slot. If we think of cards on a 1 to 10 scale, it's very possible that a 9.5 could be the wrong choice for the deck because there's a 10 available for the same slot. To see what I mean, let's look at two questions I've been asked in recent weeks. 

Thraben Inspector in UW Emeria

A few days ago, someone asked me if Thraben Inspector could work in UW Emeria, and while the answer to this question is yes—Thraben Inspector is on color and even relatively on theme for the deck—this isn't an effective way of looking at the problem. A better question is: what's the opportunity cost of playing Thraben Inspector in UW Emeria, or what would we cut from UW Emeria to play Thraben Inspector

Now, I think that Thraben Inspector could actually be pretty good in UW Emeria. It generates value when flickered by Flickerwisp and comes back from the graveyard with the help of Sun Titan. The problem is that the other options in the deck are just better. Is it really correct to cut Lone Missionary, Wall of Omens, Court Hussar, or Flickerwisp to make room for Thraben Inspector? The answer is probably no. While testing Thraben Inspector is fine, I expect that we'd find it's a 7 out of 10 but that we'd have to cut an 8 or 9 out of 10 to make room for it, which ends up being a net loss in the deck, even though 7 out of 10 is a pretty good rating. 

Nicol Bolas in Tron

One question that comes up all the time is, "Why not play a three- or four-color Tron deck to cast planeswalkers like Nicol Bolas, God-Pharaoh or Nicol Bolas, Planeswalker?" Now, there's no doubt that both of these planeswalkers are powerful and would win a lot of games when we cast them on Turn 3 or 4. However, including Nicol Bolas in Tron comes with a ton of opportunity-cost concerns. 

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On level one, we need to ask ourselves if playing Nicol Bolas, God-Pharaoh is worth the opportunity of playing Karn Liberated (because a deck—even a big-mana deck like Tron—can only play so many seven-drop planeswalkers). While I think that Karn Liberated is likely the more powerful planeswalker on its face, let's grant for the sake of argument that Nicol Bolas, God-Pharaoh is slightly better than Karn Liberated (maybe Karn is an 8 out of 10 and Nicol Bolas is an 8.5 out of 10). If Nicol Bolas, God-Pharaoh is better, we want it in our deck, right?

Not necessarily. In some cases, opportunity cost goes beyond just looking at the power of two cards, and the opportunity cost of playing Nicol Bolas, God-Pharaoh in Tron is way higher than it looks. First, we need to make room for Oath of Nissa to even cast the three-color planeswalkers with our Tron lands, and we might have to figure out a way to run other color fixing as well (like Coalition Relic) for the games when we don't draw our Oath of Nissa. This means the opportunity cost of playing Nicol Bolas, God-Pharaoh in Tron isn't just cutting Karn Liberated but cutting six or eight other cards to make our plan of casting a three-color planeswalker actually work. Even if we grant that Nicol Bolas is better than Karn (and in reality, this probably isn't true), is it so much better that it's worth dropping Chromatic Sphere and Ancient Stirrings for Oath of Nissa and Coalition Relic? Probably not. 


The point of all this isn't to discourage trying new things—there's nothing wrong with playing Thraben Inspector or Nicol Bolas, God-Pharaoh for fun in UW Emeria or Tron—but when our goal is to build the most efficient and tournament-ready deck possible, it's important to learn to think in terms of opportunity cost. There's nothing wrong with sticking your savings under your mattress, but you'll likely be better off in the long term if you invested it in a bank account, a mutual fund, or the stock market. 

As such, next time you sit down to build a deck, don't ask yourself, "Can this card work in my deck?"; instead, ask yourself, "Is this the best option for this slot in my deck?" When you do this with every slot of every deck, not only will your deck-building process improve but the finished product will be more competitive, playable, and successful as well!


Anyway, that's all for today. As always, leave your thoughts, ideas, opinions, and suggestions in the comments, and you can reach me on Twitter @SaffronOlive or at 

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