Sideboarding is one of the most complicated aspects of the game. Today, I have 7 general sideboarding tips that can apply to basically every format. They aren’t hard-and-fast rules, but they are useful guidelines that can help you build the right sideboard and to make the right swaps.

This article was partially inspired by PV’s advice to always sideboard. As he explained, it can pay off to get into the habit of shuffling your entire sideboard into your deck so you don’t let your opponent know how many cards you’re actually boarding in. But there are many other sideboard strategies that can give you an edge.

7. When in doubt on how to sideboard, add value and cut synergy

Usually, when you copy someone else’s deck list, it can be tough to figure out which cards to board in and out for various matchups. Certain hate cards, such as Shatterstorm against an Affinity deck, have fairly obvious uses, but the rest can be tricky. The following guideline can be helpful: Add answers and value-generating cards—cut synergy or easily answered cards.

The reason for this, as I’ll cover in more detail later, is that you will usually face more interactive cards and efficient answers after sideboard. In my experience, opponents will usually have the right removal spells. As a result, after sideboard you’re better off with cards that can stand on their own (like Gideon, Ally of Zendikar) or that generate card advantage (like Tireless Tracker) and you should cut cards that need other cards to function (like Signal Pest), cards whose main task is to enable other cards (like Memnite), and cards that are easily answered by opposing sideboard cards (like Master of Etherium).

It always depends on the specifics of the deck of course, and you should try to keep the core of the deck and the mana curve intact, but this guideline has proven helpful to me in the past.

6. Maximize your expected win percentage against the field

Some players build their sideboard with the goal of making every matchup (or at least as many matchups as possible) favorable. Such players might say “this matchup is already favorable, so there is no point in adding a sideboard card for it” or “I cannot make this favorable, so I’m just giving up the matchup completely.” I believe that such approaches are misguided.

In my mind, the goal is not to maximize the number of favorable matchups across the field—the goal is to maximize the expected match win percentage against the expected field. (I’m simplifying things here a little bit for the sake of the argument. A better goal would be to maximize expected prize winnings, which is not the exact same thing in general. But I am abstracting this away for simplicity.)

To illustrate my point with a simplified example, suppose that there are only two decks in the metagame: aggro and control. Both take half of the field, and the aggro-control matchup is 50-50. You have a sweet brew that, without a sideboard, would have a 60% match win percentage against aggro and 40% against control. Sideboards in this hypothetical format consist only of one single card, and you have the option between Radiant Flames and Negate. If you add a Radiant Flames to your sideboard, then you can increase your aggro matchup from 60% to 90%. If you add Negate to your sideboard, then you can increase your control matchup from 40% to 60%.

In this case, the correct addition is Radiant Flames—even if Negate would give you favorable 60% matchups across the board, Radiant Flames would yield a higher expected match win percentage (half of 90% plus half of 40%, i.e., 65%) against the field as a whole. That is usually how I look at things.

5. Make sideboard plans to ensure that the numbers work

Fixed sideboard plans are perhaps overrated, as you always have to make small adjustments depending on the specifics of your opponent’s deck. But it’s valuable to draw up these plans while you’re in the process of building your sideboard, as it helps you have the right number of cards for every matchup. You always want to match the number of cuts with the number of adds.

As an example of what might go wrong, suppose you fill your sideboard with 10 anti-aggro cards, but then during a tournament you discover that your 10th sideboard card is just as good as the 10th card you would take out. Clearly, it would’ve been better to think things through in advance—you could have changed your sideboard and used those slots for another matchup. In general, devoting too many cards to one matchup results in diminishing returns, and you should always check how many main deck cards you’d even want to replace in every matchup.

This concept can be taken further by what Zvi Mowshowitz once called the “elephant method”: Write out realistic 60-card post-board configurations that you’d like to have in all major matchups, and then try to make the unique cards in those lists add up to 75. So instead of thinking of what you want in your main deck and what you want in your sideboard, think about what your post-board configurations should look like against each opponent, and use that knowledge to fine-tune your 75. As a final step, you then split those 75 into 60 main deck cards and 15 sideboard cards. This deck building approach comes with a variety of benefits. For example, you can ensure that your 75 contains no more than 15 horrendous cards in any matchup.

4. Don’t overboard situational answers, especially on the play

If your opponent beats you with Lingering Souls in game 1, you might consider bringing in Illness in the Ranks. Likewise, if you’re playing Modern Burn and some (but not all!) opponents have Leyline of Sanctity in their sideboard, you might consider bringing in Destructive Revelry. Yet, this sideboard strategy is risky, as you could easily find yourself with a dead card in hand. If you sideboard too many situational answers in an otherwise proactive deck, then you could  make your deck worse, not better.

To illustrate with some numbers: Against a deck that has no token producers other than Lingering Souls, Illness in the Ranks might have a value of 9 on a scale of 10 if your opponent drew Lingering Souls. But your opponent only has at least one of their 4 Lingering Souls in their top 10 cards (i.e., turn 4 on the play) in 52.8% of the games. In the other games, Illness in the Ranks would be 0 out of 10 by turn 4, yielding an expected value of 52.8% * 9 = 4.8 at that stage of the game. If the format is such that games end by turn 4, then you would be better off with a card that is always a 6.

Naturally, this calculation depends on the relative impact of their card, the length of the game, and the consistency of your opponent’s deck. For instance, if the opponent would have 8 token producing cards in their deck, then the expected value of Illness in the Ranks after they saw 10 cards increases to 7.1. And if the opponent has a lot of card draw spells or ways to draw out the game so that they might see 16 cards in an average game, then the expected value of Illness in the Ranks would grow to 6.5 even against the 4 Lingering Souls deck.

It can be hard to assign proper weights to all of these aspects, but as a general rule of thumb, I only board in an answer if it can target at least 8 cards in my opponent’s deck or if it my opponent basically cannot win without that card. I rarely find it worthwhile to bring in a card that can only target 4 cards if it’s not absolutely crucial to their strategy and if I expect games to be short. This is especially true for proactive decks and on the play, where I try to focus more on threats than answers.

3. Even if a card is always boarded in, it does not necessarily belong in the main

Every time I post a sideboard plan that involves boarding a certain card in every single matchup, a lot of people comment with the suggestion to put that card in the main deck. No matter how well-intended such comments might be, a sideboard plan with this feature need not indicate a deck building flaw.

First, you might have different cards to take out in different matchups. For example, your main deck might include a cheap removal spell that is a 9 versus aggro and a 4 versus control, as well as a piece of countermagic that is a 4 versus aggro and a 9 versus control. In that case, it can pay off to have general utility card valued at 6 in your sideboard so you can always replace your main deck 4. Note that when the metagame is 50% aggro and 50% control, your main deck cards have an expected value of 0.5*4+0.5*9=6.5, which is better than the all-round 6 in this example.

Second, post-board games might play out in a different way. This is more common. Usually, opponents will bring in cards that interact with your strategy, which means that post-board games are often slower and more grindy. As a result, sticky threats or strong late-game cards become more valuable in games 2 and 3, while synergy-driven cards become worse. This is why aggro decks often have planeswalkers in their sideboards that come in for every matchup.

So it’s fine to have sideboard cards that you board in against everyone. Or, for analogous reasons, a main deck card that you board out against everyone.

2. Board against their post-sideboard configuration

This ties in with the previous point. Post-board games are simply different than pre-board games! As an example, there are control decks that bring in Thing in the Ice in every matchup because their opponents will often board out their removal spells that were dead in game 1. So Thing in the Ice might be bad in game 1 but great in game 2 simply because the expected configuration of your opponent has changed.

Another good example from the recent Standard format is Mardu Vehicles—Magma Spray might be much better than Negate against their game 1 configuration, but when they sideboard out Scrapheap Scrounger and sideboard in Nahiri, the Harbinger, it’s the other way around! So you should always try to predict what your opponent will be doing and board against that. Bringing in cards that would have been good in game 1 is a common mistake, and one that you should try to avoid if they might transform.

Sometimes, you’re best off with a transformational sideboard yourself. I remember how I had trouble beating Pithing Needle and Cranial Extraction post-board with my Greater Good combo deck many years ago. So I just loaded up my sideboard with alternative win conditions, boarded out my Greater Goods, and turned my opponent’s trumps into dead cards.

Another thing to keep in mind is that you should not make opposing sideboard cards better. If you’re playing Affinity in Modern, then Ethersworn Canonist may look like a good sideboard card against combo decks, but if opponents are bringing in Ancient Grudge against you, then you may be better off with Rule of Law instead.

The key lesson is to largely ignore their game 1 configuration. The nature of a matchup can change completely after sideboard.

1. Adjust depending on play/draw

The nature of a matchup also depends on who is on the play and who is on the draw.

When you’re on the draw, you’re behind in the tempo and damage race from the start. But you do have an extra card to work with. As a result, you can safely cut a land and shave a few cheap threats. Meanwhile, you should add efficient answers and catch-up cards. Fatal Push, Disdainful Stroke, and Radiant Flames are examples of spells that are better when you’re on the draw, as they allow you to steal back tempo. High-toughness creatures are good too, especially in Limited. By contrast, Toolcraft Exemplar, Goblin Rabblemaster, and Painful Truths are much better on the play.

When you’re on the play, you might want to add a land if you have one, but more importantly, you are in a prime position to capitalize on opposing stumbles. If your opponent draws too many tap-lands or slow cards, a good curve of threats can easily steal a win. After all, you get to deploy your cards a turn ahead of them. At the same time, you’re down a card, which means a strategy filled with 1-for-1 answers and reactive cards won’t be as effective. Instead, I prefer to focus on threats and aggressive cards. Planeswalkers are also better on the play because it’s more likely you can deploy them on a favorable board state where you can protect them. But generally speaking, be more proactive.

Conclusion

I hope I have provided some useful insights. But sideboarding is a deep topic, and I surely haven’t mastered every trick of the trade. What are your own favorite sideboard strategies? Do you have any great examples or tips? Please share them in the comment section below!