The Abyss, Moat, and Time Walk Into a Bar: An Abstract Guide to Sideboarding

Sideboarding is an art form in tournament Magic and one of the most difficult skills to hone. If you can sideboard better than your opponent, there’s a trove of potential wins ripe for the taking! Games often come down to luck of the draw, but superior tactics are the best way to ‘make your own luck.’

I’m going to share the theory I use when building and using my sideboard, no matter the format I’m playing. It’s abstract but gets to the root of how I understand match ups and use my sideboard to improve my odds.


I don’t take an elitist approach and say that sideboard guides are bad and people should feel bad for writing or using them. In fact, they are a great resource for new players as they provide a baseline starting point for thinking about and approaching matchups. With that said, sideboard guides can only take you so far… Investing 15 minutes into copying a guide won’t make you worse for the effort, but there is a ceiling to how far it can take you and here’s why:

1. Sideboard guides are known commodities. Experienced players anticipate and exploit them.

When I’m preparing for a tournament, my research is to read the weekly articles and study how my potential opponents are being told to board against the deck I’m planning to play. It’s no fluke, most people at an event will board precisely how content informs them to do so.

I also have a sideboard guide in my deckbox, but unlike most, mine is a list of how opposing decks are boarding against me.

2. Metagames move fast and published lists are old news.

While published lists create a solid baseline to start from, they are never at the cutting-edge. By the time the weekend rolls around, people are ready.

3. There’s no sideboard guide for Limited!

While the gains of innovating sideboard technology are only a slim (but tangible) advantage in a world of guides, it is a huge boon to leveling up your Limited game. In Limited, the use of the sideboard is all about determining what is important, why it is important, and what to do about it.

At Grand Prix Boston, I had an interesting Sealed pool that built two reasonable decks. The first was B/R Aggro with multiple Tormented Soul and Dark Favor backed up by lots of burn.

On the other hand, I also had an above-average Jeskai deck (that only overlapped 3 Searing Spears) on a splash.

I started BR Blitz and always transformed into Jeskai Control for game two. I had both decks sleeved and did my best to make the 37-card swap without my opponent noticing:

Transformational Sideboard Plans is an added tactic that differs from the Game 1 approach. In Vintage, for instance, players will sometimes do wild things like sideboard 4 copies of Oath of Druids, Emrakul, the Eons Torn, and Elesh Norn against creature decks. You don’t need a Forbidden Orchard if you know an opponent is playing lots of critters.

A 37-card substitution is about as transformational as it gets! Not only did the approach take opponents by surprise, but completely invalidated their sideboard choices. The cards that are good against a BR Blitz deck are not typically good against Azorius Control.

Obviously, it’s great to get one good Sealed deck and fantastic luck to make two from the same pool; nonetheless it’s important to make the most of good opportunities.

4. “Outside the Guide” thinking allows you to invent and utilize your own ideas.

Inventing your own tech, bringing it to life, and seeing it win games is one of the most satisfying experiences in Magic. It’s also a tangible way to gain an advantage in a tournament. If you’ve got the better deck and better plans an opponent cannot account for–that’s the high ground right there. The more you practice the sideboarding skillset, the more you’ll learn: what works, what doesn’t, and why.


I can’t remember the exact context I heard Patrick Chapin say that, but it’s a concise and fascinating way to think about what cards do. Ten years later, the statement has stuck with me and continues to inform how I think about Magic theory.

For reference:

Time WalkMoatThe Abyss

What does this mean and how can it possibly be true?

The key is each category informs “what function” a card will fill. The categories are abstract and the more fluidly you are willing to apply them, the more useful they become to understanding the relationships between cards. Don’t get too bogged down in thinking too literally about the corresponding name assigned to each archetype. After all, it’s just a random phrase uttered by a Hall of Famer a decade ago!


Trade Caravan (1)

Most interactions are “trades.”

Delver of Secrets // Insectile AberrationLightning Bolt

An opponent plays a Delver on Turn 1 and it eats a Bolt. It’s not exactly the same, but it’s a relatively even trade in terms of resources and mana.

Not every card we put onto the stack allows us to run away with the game. The card we put onto the stack that does run away with the game is that one an opponent cannot reasonably trade with at the time.

In most contested games, players make trades until somebody cannot make good exchanges. This is the point in the game where an advantage is established and the advantaged player pushes that advantage and the disadvantaged player seeks to mitigate the damage to “draw out of it,” either in the form of an answer or a bigger threat.


Cards function as Time Walks when they advance you further into your plan more quickly than an opponent can trade.

Here are some basic ones:

Reflector MageRavenous ChupacabraFlametongue Kavu

1-8-7. 2-for-1. When the turn started our opponent had a threat and we didn’t, but when it ended we had a threat and they didn’t. Flip! Flip! Flip-a-delphia!

While these cards tend to be associated with card advantage, it cannot be understated the amount of tempo they generate against aggressive decks.


Remand also has the nasty ability to function as a Time Walk in blue combo and combo-control decks. Since these decks tend to ‘bide their time,’ until they’ve reached critical mass enough to ‘go off’ trading two mana to cycle a card and force an opponent to repeat the same sequence later is an effective way to advance deeper into the game.


I’d like to live for another turn. Try again next turn. If an opponent’s primary way to win the game is via combat, this type of effect will extend the game an additional turn.

A card can function as a “Time Walk” for the purpose of this theory without equating to a full turn worth of value, whatever that means. Even if the gain is minimal, it’s still useful.

The most common way tempo is leveraged is to “double-spell” as early and often as possible. If you can play two cards a turn and the opponent can only play one, chances are you’re doing something right!

Lightning BoltTarmogoyf

On turn three I untap, cast Lightning Bolt on my opponent’s threat and play a Tarmogoyf. My opponent is facing a threat and doesn’t have one of their own. If my opponent untaps, plays a third land, and must choose between casting one of two 2-drops Tarmogoyf or Terminate, it’s clear my sequence was more efficient.

Cheap interaction, such as removal or permission, is a great way to generate tempo advantage and impacts how the game will play out. The more awkward it is for an opponent to deal with your pressure, the more tempo can be seized, and the advantage of tempo quickly translates to more tangible advantages.

There are other types of “Time Walks” as well:

Show and TellTendrils of AgonyUrza's Tower

“Combos” function as Time Walks, since they generate huge bursts that accelerate directly into an endgame scenario. Any time you can execute a sequence of plays from which an opponent cannot immediately restore parity to the board, you’ve put yourself into a great spot to win.

Chittering Rats

While most “Time Walks” tend to revolve around mana, there are certainly game states where mana isn’t important anymore. If you catch an opponent holding a dead card with a Chittering Rat in a topdeck war and force them to draw it again, you’ve clearly pulled yourself a turn ahead.

“Time Walks” are advantageous trades that generate some sort of advantage. While I’ve only described a handful of examples there are thousands of ways different decks try to pull ahead: Combos, Double-Spelling, Buying More Time, Ramping, Pitch Spells, and Combat Tricks are just some of the thousands of ways it can be accomplished.


This category of cards that protects us (like a Moat around a castle) from opposing threats.

The card Moat invalidates all non-flying creatures but also invalidates future non fliers drawn from the deck as long as it remains in play. A great blocker like Tarmogoyf can function as a Moat if it creates a situation where an opponent can’t advantageously attack.

Chalice of the VoidBlood MoonRule of LawLeyline of the VoidIvory Mask

Actual Moat” invalidates non-fliers, but the above cards (typically called “hate cards”) invalidate other subsets of cards and strategies.

Blood Moon is a Moat for nonbasics. Leyline is a Moat for graveyards. Etc.

While most Moats tend to be permanent that make it unlikely an opponent can win while on the battlefield, there are also “Moats of the Mind.”

ExtractCranial Extraction

Some decks play precisely one way to win the game and Extracting that card essentially hamstrings the entire strategy. What is or isn’t an effective “Moat” is variable depending upon context. Extracting a deck with one win condition is a hard lock, whereas Extracting a Zoo deck is foolish.

Narset, Parter of VeilsTeferi, Time Raveler

Standard is less defined by Moats than older formats, but they still play a role. Against a deck like Simic Nexus, both Narset and Lil’ Tefs are effective at invalidating huge portions of their plan. They are also difficult for a Simic deck to remove once resolved. Effective and resilient is the high watermark of an ideal sideboard card.


The Abyss” are proactive cards that attack at least one of an opponent’s available resources, directly or indirectly, by forcing an opponent to interact or risk running out of time and resources.

A 10/10 is an obvious The Abyss if unanswered. An opponent can only take 10 so many times before they either die or start chump blocking away resources. If you can sustain a threat and repeatedly deal damage or force an opponent to sacrifice resources, it’s obvious that headway is being made.

Your life total is a resource. When your opponent deals damage to you, they are taxing one of your resources. It’s not always the most important resource in a given game state. Sometimes mana is what matters. Sometimes cards are what matters. Sometimes a Moat is what matters. But it is a resource and it does matter.

The Abyss works outside of dealing damage as well:

Disrupting ScepterJace, the Mind Sculptor

Planeswalkers are a great example of Abysses, since if unanswered they continue to generate resource advantage for your cause. While it’s obvious “Actual The Abyss” eats an opposing creature each turn, the inverse of repeatedly drawing extra cards or netting resources achieves a comparable result as the game drags on. If an opponent is already behind and can’t beat the Jace on the board, it is a tall order to beat it later after it’s drawn a bunch of extra threats and answers.

Some cards fill multiple roles–Tarmogoyf is a great example as a competitive card because it can potentially fill all three roles.


TARMOWALK: An efficient way to get ahead early and easy to double spell with.

TARMOMOAT: Nice 2/2s. Meet 4/5.

TARMO ABYSS: Brings the beats, forces blocks.

So, is Tarmogoyf a Moat, Time Walk, or The Abyss? Irrelevant. It’s a Tarmogoyf. The point of the exercise is to learn to identify what role specific cards play from one matchup to another and evaluate how effective each card is at doing its job.


Identifying cards that are effective or ineffective at filling the role they will play is among the most useful information in the game. It’s the difference between making sideboard decisions that are fine and ones that are precise. In older formats, where the cardpool is large and the decks linear, powerful, and highly synergistic, sideboard play often centers on the interplay between Moats and an opponent’s ability to trade with them.

Bazaar of BaghdadDread Return

In Vintage, there are only two realistic ways to defeat Dredge. Since they generate free, recursive creatures through graveyard synergy, it isn’t reasonable to Lightning Bolt every Zombie that shambles your way.

Rest in PeaceLeyline of the VoidGrafdigger's Cage

While it is possible to take a “Time Walk” approach and execute a combo, it’s a tall order to be consistently faster through a swath of Cabal Therapy. Dredge is extremely adept at generating its own flavor of Time Walks in the form of free S.D.A.G. (Stuff Dredge Always Gets).


The most effective foil to a linear deck like Dredge is via strategic Moats, in this case graveyard hate. The Dredge player will also understand what the battle lines are and will likely bring in cards like Nature’s Claim or Chain of Vapor to deal with your Moat. In anticipation of Nature’s Claim, the other player may bring in Flusterstorms or Mental Missteps to protect their Moats from removal.

I picked the Dredge example because it illustrates the dynamic I’ve laid out pushed to the most extreme.

The Hierarchy of things that Matter in a Post-Sideboard Dredge Game

  1. Does the opponent have a graveyard Moat?
  2. Literally, everything else.

After sideboard, the most impactful and important interaction will revolve around whether a graveyard hate card is deployed or not, and then whether the Dredge player can remove it. Sure, there’s other stuff that sometimes matters, but this will always matter. Not only will it always matter, it will always matter a lot.

In the abstract, this is how all sideboarding works, but on a much, much less compressed level. There are few cards that impact other decks as dramatically as Leyline impacts a Dredge player on turn zero. The more clearly you can identify which cards matter and why, the better your sideboarding packages can become.

We don’t need much theory to understand that Leyline of the Void is good against a deck that runs all its offense through the graveyard. I started with the most obvious example, but now let’s take it to the other extreme. I’ve always pushed my sideboard play in Limited. I’m willing to go deeper and do ridiculous things if I think it improves my chances.

Some things are obvious:

What matters against UW fliers? Not dying in the air.


What matters against a bomb rare equipment? Not getting Abyss’d on your turn and Moat’d on yours.


What matters in a deck with an ungodly amount of removal? Not getting run out of threats.

Mind RotRecover

What matters against a go-wide Token aggro deck? Not getting run over and not giving them infinite time to find Overrun.

Boiling EarthNausea

There are functional reprints of these types of cards at common in virtually every Limited format and these maneuvers are as basic as they are effective.


Another quick thing to keep in mind. Make sure the things you are boarding for actually matter!

“I saw five artifacts, so I boarded in Shatter.”

“But their artifacts were Thopter tokens and Field Creepers.”

Do they have something you really want to Shatter? No? Leave Shatter in your box where it belongs.

The last example I want to touch on is a fun one from an Hour of Devastation Limited Grand Prix a few years ago. I had a medium Sealed pool defined by lack of removal and decided to build a focused beatdown deck that used combat tricks to push through blockers. Certainly not ideal, but passable.

In one match I played against an opponent who had a deck that wasn’t aggressive but featured two insane bombs:

The Scarab GodThe Locust God

In our first game, I came out of the gates with one of my strongest possible draws but ran into a Mythical Buzzsaw that easily Moat’d my assault and then Abyss’d me into submission. As I pulled out my sideboard, I had to figure out how I could win.

Clearly, the game-warping mythics were what was important. In fact, they were so important to the matchup I believed if my opponent drew those cards it was unlikely I could realistically win.

My options boiled down to:

  1. Hope opponent doesn’t draw a God from a 40-card deck.
  2. Hope my opponent gets mana screwed.
  3. Hope I’m able to win the game on turn 5 or 6 if a God is drawn.

I stuck to my guns. Opponent mulliganed to four both games and I won. Great story, right?

Just kidding. Hoping is only the best plan when there is no plan. I had also just lost a game where my deck gave me a great start, so I knew running my opponent over was a pipe dream. I decided on option #4: buck-wild transformation.

My blue cards were not good and didn’t build a coherent deck. At least, not a deck that was coherent enough to field against an open field. However, I noted that my sideboard had several counterspells capable of answering either God. Specifically, I had two Jace’s Defeat.

Supreme WillCountervailing WindsJace's Defeat - Foil

As it turns out, my opponent didn’t get mana screwed, drew their Gods, and I was able to counterspell them each time and take the match. It was one of those satisfying wins where afterward you think, “I cannot believe I just pulled that off!”

The important part of the example was identifying not only “what was important,” but also identifying “how important.” It turns out that answering those gods was the most important thing.

The key to sideboarding is learning what is important and which cards are effective in their roles. It’s also about anticipating the types of adjustments an opponent is likely to make: Are they going to Moat you? Time Walk you? Or, Abyss you? What is the most effective way for you to work around it?

You don’t have to call these things Moats, Time Walks, and Abyss, but what these categories represent are the real and tangible dynamics from which advantage is created and used.


Moat, The Abyss, and Time Walk into a bar. The bartender says, “Bar is reserved seating for the evening. You fellas on the list?” Before they can answer, an Eternal player seated on a barstool bursts out laughing, “What kind of a newb doesn’t even know that Moat, The Abyss, and freakin’ TIME WALK are on the Reserve List!?” The bartender, clearly a little embarrassed, says, “I didn’t realize you were all so famous. Take a seat.” They sit, order a round, and after a minute, Moat asks,

“So, what kind of event is going on tonight?”

“…Yu-Gi-Oh! Regionals.”

“Cheque, please…”

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