Advanced Sideboarding

By guest author FlyingDelver

You’re sitting across from a Dredge player at a tournament. You’ve just lost game one, and you reach for your deck box, hoping the match-up gets better post-board. You unfold your small side-board guide and start methodically swapping out your dead cards for more relevant ones, just as you have every match-up before.

Sideboarding often becomes a cookie-cutter guide of “cutting x copies of card A and bringing in x copies of card B.” It’s simple, and can become a habit to rely on. However, knowing why we are sideboarding certain ways and when to do so is a great skill to obtain. GBx decks naturally don’t have a linear gameplan to follow. Other than casting a Tarmogoyf on turn two and turning it sideways, GBx matches vary greatly turn to turn. They seek interaction; the more we are allowed to interact with our opponent the better our deck can function. This means we want to tune our deck to perfectly combat our opponent. Since we are a strategy of interaction at heart, our sideboards are far more precious to us than to other less interactive decks.

GBx decks plan A is to stop the opponent from executing their plan A.

However, with the vastly open modern format, this is impossible to do when we only have our 60 maindeck cards. Luckily, we have sideboards. And I really mean luckily.

“Maelstrom Pulse” by Anthony Francisco.

Most people immediately grab their sideboards after game one in order to look for the  cards they want to bring in for that particular match-up. The problem is that you are likely focusing on what cards you want to bring in without taking your maindeck into account. It’s difficult to consider your maindeck that way, because you subconsciously put a barrier there, treating your maindeck and sideboard as separate. But sideboarding shouldn’t work that way, especially for GBx decks which are very dependant on their sideboards.

To overcome this subconscious separation, try this: after finishing game one of a given match-up, take your 15 sideboard cards and shuffle them right into your deck. By doing that, you are actively erasing that mental barrier of sideboard and mainboard, and creating a gauntlet of 75 cards. Your goal now is to make the best 60 card deck for the match-up out of your 75 cards. Go through your deck and remove every card you don’t want. This simple trick is actually nothing new, as many pros have already suggested this way of sideboarding. It really helps to understand how to sideboard by viewing it in a different perspective. Plus, you are getting the added bonus of your opponent not getting to know how many cards you exchanged. You shuffled 15 cards into your deck and removed 15 cards afterwards. You are giving away no free information. This way of doing it will be uncomfortable and difficult to execute at the start, but practicing it at home before the tournament will get yourself comfortable with it pretty fast. Pretend to play against a difficult match-up and just focus on sideboarding for it in particular.

Here are some other advantages of sideboarding 15-In, 15-Out (besides disguising the amount of cards that got exchanged):

  • You don’t get biased about certain sideboard cards which look good in vacuum, but might not be the card you want given the context of your deck. If your deck has better cards otherwise, then the card you are looking at can be cut.
  • You can pay attention to the manacurve you are changing, which might open up the possibility to cut a land.
  • You are forced to really think about the match-up you are playing. This evolves your skills and can help you to find the best sideboard options against new match-ups.

Keep in mind that we are always adjusting our deck in order to tackle our opponents sideboarded deck. For example, it might be appealing to bring in shatter effects against Aether Vial strategies, but Aether Vial is usually a bad card in attrition-based match-ups in the first place. It’s a horrible topdeck and since the Vial deck needs to expect an interactive game with lots of removal and sweepers, Vial becomes less effective. In fact, most Vial decks will board out the card against us, so bringing in extra shatter effects like Ancient Grudge is definitely not worth it.

This is a good method for basic sideboarding. Next, let’s check out some of the more advanced nuances of sideboarding.

Shaving instead of cutting

This aspect of sideboarding is pretty hard to master. The concept means that you should not think of cards being simply bad and good against a given match-up. Sometimes the question should be:

Is the last copy of a given card better than the first copy of a sideboard card?


How does the power level of a given card change depending on whether you’re on the play or the draw?

When you are able to accurately answer those questions, you’ll be able to think with more flexibility about the proper numbers of each card. The amount of cards to run in the deck obviously reflects the frequency we want to see the card in the game.

  • Playing 4 copies of a card: We want to see the card as often as possible per game. We are happy to draw multiples and it could also be an essential part of our strategy.
  • Playing 3 copies of a card: We want to see the card about once on average in a given game. Drawing multiples is not the worst thing and sometimes wanted, but often we are fine with having just one copy.
  • Playing 2 copies of a card: We are less exciting to have this card in the opener, it is less essential and more geared towards specific situations. Endgame bombs or costly cards fall into that category.
  • Playing 1 copy of a card: We only want this card in very specific situations or moments in the game. In an average game, we don’t want to have this card in the opener.

Let’s look at an example of this concept. This is my latest Rock list:


If I were to sideboard against one of the popular decks of modern right now, the Bant Spirits deck, I would have a couple of bad cards among my 75. Let’s break it down in greater detail: Out of the sideboard, I don’t want Surgical, Spellbomb, Duress, Nissa, Damping Sphere or Fulminator Mage. So those cards certainly won’t end up in my game two configuration. The ‘maybe’ options are Choke and Kitchen Finks, but I am not fully convinced when looking at those cards in a vacuum. In that sense it would require some worse cards from the maindeck to cut in order to bring those cards in. The only cards I absolutely want in are Deathmark, Damnation, Grafdigger’s Cage and Collective Brutality. Since the Spirits deck is a creature-based strategy, I basically want every card in my deck that can kill a creature, even if it’s not super reliable such as Brutality. However, Brutality has some very strong upsides in being able to snag a Collected Company from the opponent’s hand before it gets cast.

So that means I have four cards I absolutely want, and two cards I could see being boarded in for certain circumstances. If we look at the current maindeck, I only see two cards I absolutely want to cut: Both copies of Thoughtseize. The life totals are just under too much pressure to justify them. I have Brutality for Collected Company as well and other than that, Inquisition of Kozilek can deal with the rest just fine. So, beyond Thoughtseize, which cards do I want to cut? I have my eyes on Liliana of the Veil, Dark Confidant, and Tireless Tracker. They are not completely bad like Thoughtseize, but they aren’t the best either. Dark Confidant increases the pressure on our life total, Tireless Tracker is way too slow for that fast match-up, and Liliana of the Veil doesn’t line up well against Noble Hierarch and their smaller creatures.

So, I have two cards I absolutely want to cut and four cards I absolutely want to bring in. Now, of the mentioned cards, what do I want to shave? And even further, do I want to shave more than two cards in order to fit in the extra “maybe” cards from the sideboard? I could simply cut both Tireless Trackers, which gives me enough space to implement my four wanted sideboard cards and call it a day, but that would be too easy. I didn’t apply the theory I was mentioning before. All these decisions depend on whether I am on the play or draw and on the basic concept of how many copies of a card I want to see in any given game. The first question is rather easy to answer:

Do I want to draw multiple Dark Confidants against Bant Spirits?

The answer is clearly no. And this answer doesn’t change whether I’m on the play or draw. So I want to cut at least one copy of Dark Confidant. Do I want to cut more copies of Dark Confidant as well? To answer this question, we should look at the dynamics of being on the play or draw. Dark Confidant puts pressure on your own life total and the Bant Spirits deck does that already as an aggressive strategy. When the Spirits deck is on the play, the pressure on our life total is much higher. Dark Confidant gets a lot worse on the draw, so I would definitely consider cutting one extra copy of Dark Confidant.

What about Liliana of the Veil? Liliana of the Veil is already only present in the deck as a three-of, which means we aren’t super likely to draw multiples, although it can still happen. On the draw, Liliana of the Veil also gets worse. I think she is actually somewhat good on the play. So, if we assume we are on the draw, we said we want to shave an additional copy of Dark Confidant, but we also said Liliana is worse on the draw. So, since we already have three cuts fixed (two Thoughtseize and one Dark Confidant) which card should be the fourth cut? Here, the answer is Dark Confidant. Liliana might not trade with a big creature from the Spirits deck, but she does still help maintain the mentioned philosophy of having access to every card that can kill a creature. So, in that sense, I would cut the second copy of Dark Confidant before I cut the first copy of Liliana of the Veil on the draw.

We are still not done though– we still have to decide whether we want to cut additional cards from the maindeck to bring in our ‘maybe’ cards or not. So, the question now becomes: Do I want Finks/Choke over the third Liliana, the second Tracker or the second Dark Confidant on the draw? We’ve already shaved enough Dark Confidants so I would shave the first copy of Liliana before cutting more Dark Confidants. Also, Choke is a card which could potentially cripple Spirits (especially since they board out Vials) but not on the draw; it is much stronger on the play. Despite that, Choke might not line up well with the non-island lands drawn by the Spirits player. This narrows the question down to: Do I want Finks over Liliana or Tracker? Tracker is always a little unexciting, regardless of being on the play or draw, but on the draw we are more likely to draw into lands which Tracker could make a little bit more useful as an endgame finisher. And because our life total is under a lot of pressure on the draw, some life gain from Finks could be nice. In addition it also blocks Geist of Saint Traft. All things considered, I would cut the third Liliana for the Finks on the draw.

If we add everything up, we end up with the following plan on the draw:

  • We take out one Dark Confidant because we don’t want multiples in this match-up where life totals are pressured hard.
  • A second copy of Dark Confidant gets cut because we are on the draw.
  • Both Thoughtseizes are bad due to the life loss and amount of overlapping targets with Inquisition of Kozilek.
  • Liliana of the Veil gets cut as she is worse on the draw, but she is favoured over Dark Confidant as she does at least follow the philosophy of “getting access to everything that kills a creature”. For that, only one copy gets cut.

And there we have a well thought-out sideboard plan against Bant Spirits on the draw. Remember everything you do should have a specific reasoning behind it. Always ask the question: What am I trying to accomplish? Simple guides that only show the numbers of ins and outs of a given match-up, while convenient, are not fully helpful. As a GBx pilot, we should seek for understanding of different match-ups in the first place in order to be successful, and that also applies to sideboarding.

“Overgrown Tomb” by Rob Alexander

Sideboarding lands

This concept is about adjusting your land count after you’ve adjusted your mana curve. Lands are rarely sideboarded, which is a missed opportunity. If you’ve ever complained about getting flooded too often with your 25-land Jund deck, I would advise figuring out a plan to adjust your manabase according to the match-ups you face.

There are many aspects to keep in mind when cutting lands against various decks. The decisions can be difficult to make, but these are the points to keep in mind:

We want a proper land count against fast strategies.

Usually, games against aggressive strategies won’t last very long. Either you will be overwhelmed very quickly and can’t come back or you were able to answer what your opponent was doing and able to stabilize. You may be tempted to cut lands in these matches, because you don’t want to flood out, but we want to hit our land-drops in the first few turns to be able to cast our spells in the first place. Fast match-ups are more punishing than any other for missing land-drops. You won’t have time to deploy excess spells in the most crucial moments of the game anyway. Flooding might be a possibility, but since the average game doesn’t last very long, the nature of the games are more likely to be determined by the opening hand you keep. If you keep a hand with two spells and five lands against Humans for game two, you are partly responsible for potentially flooding.

We want fewer lands against grindy match-ups.

Grindy match-ups usually last longer by nature. There’s often more time to draw out of a screw here because they typically don’t put you on a very fast clock. However, drawing a string of lands in the late game often means lights out. In those match-ups, the endgame threats are so dominant and powerful that we can’t come back after one or two dead draws. For that reason, it makes sense to err on the side of a lower land count.

We need less lands on the draw than on the play.

On the draw, the extra card we get helps to find land-drops on its own. On average, the probability of hitting land-drop X on turn X stay the same if you cut one land on the draw. In other words, due to the extra card drawn, the probability of hitting land-drops on time increases. This means we can cut a land and still maintain a similar probability compared to being on the play.

We always want a proper land count for the respective manacurve.

This is always the goal, whether you’re building a deck, or deciding how to sideboard lands, this is one point that you should always have in mind. The problem becomes the contradiction in some of these strategies. For instance, against faster match-ups, we typically lower our manacurve, so that should mean we are able to cut a land. However, as discussed before, the nature of the match-up makes it so that we want to hit land-drops in a timely manner and therefore don’t want to cut lands. In the grindy match-ups, our manacurve typically gets higher as we want access to more expensive endgame threats, and that would mean we want to keep all lands. But we also want to prevent flooding. So what should we do?

Look at the match-up individually. How much do you lower or increase your manacurve? For example, against creature based aggro decks, we often side in Damnation. As a four mana card, it doesn’t really help to lower the curve much, so cutting a land wouldn’t make sense. We want to be able to cast a timely Damnation if needed. In fact, aggro match-ups are so fast and linear at the moment, the need to hit land-drops on time and be able to cast relevant interaction is much more important. So, for those match-ups we can summarize:

Only cut a land against fast linear decks if you are on the draw AND are significantly lowering your manacurve.

We can follow a similar guideline when sideboarding against opponents with long-game strategies. On the play, the need for the extra land is higher, but we still want to balance the manacurve and flood prevention.

On the draw against grindy match-ups, cut a land if possible. On the play, keep the land if you are significantly increasing the manacurve.

“Liliana, the Last Hope” by Anna Steinbauer.

Sideboarding is one of the most difficult skills to master in competitive play. There aren’t many hard-and-fast rules that will apply to every situation, and in a tournament you have to make tough decisions in a short amount of time. The guidelines above should help to bring some context to the sideboarding decisions you make, and encourage you to think more critically about why you’re making them. Always think about: “What am I trying to accomplish?” By practicing these sideboarding skills, you can often take those close skin-of-your-teeth matches and tip the scales a bit more in your favor.

Until next time,


FlyingDelver is deeply involved in the G/Bx Modern community as the author of MtGSalvation primers for Jund, Abzan, G/B Rock, as well as the administrator for the G/Bx Midrange Discord, and part of the administrative team for the G/B Rock Facebook page. Please find relevant links in the external resources section. You can support FlyingDelver through his Patreon page.

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