1. Sideboarding Answers Improves Your Aggro Deck
Sideboarding is a prime opportunity to make your deck worse. To put it simply: for each sideboard card you add to your deck you must remove a maindeck card. It is common practice in deckbuilding to fill the main deck with consistently powerful cards and to put context-dependent, niche cards in the sideboard. If you are unfamiliar with your deck or the format it is especially plausible that you might over-sideboard. People regularly sideboard out threats for answers during sideboarding—this is correct if you wish to take the control role or if you can not beat your opponent’s threats without specific answers. So there are some situations where sideboarding answers with your aggro deck is correct:
Taking a controlling role: The most common scenario for an aggro deck to switch roles is in a mirror match. When you decide to be less aggressive you are making a choice to try to try to extend the game and win the long game. In order for it to be correct to play toward the long game you will need powerful sideboard options to compensate for hamstringing your regular game plan. Let us imagine that you are playing an Abzan Aggro mirror match and you have access to Duneblast and Elspeth in your sideboard. These cards are not synergistic with your main deck—nonetheless their impact is high enough to justify adjusting your game plan for.
Unbeatable Threats: For example—Return to Ravnica block, Mono-Red vs. Esper Control. The Esper deck contained almost no creatures except for Blood Baron of Viskopa. Despite Esper’s lack of creatures Mono-Red players were correct to board in Mizzium Mortars in place of some of their threats. Mono-Red did not want to take a controlling role, however because of how effective Blood Baron was against red it was necessary to have an answer in Mizzium Mortars. In the majority of circumstances an aggressive deck cannot risk sideboarding in answers as it dilutes the density of threats. Aggressive decks make up for their lack of individual card quality by shortening the window for an opponent to take advantage of their better, more expensive cards. One random Tormented Hero backed up by four Hero’s Downfalls/Murderous Cuts is unlikely to win a game—however two Tormented Heros and a Bloodsoaked Champion backed up by two removal spells just might do the trick.
I provided a couple of scenarios when you should be sideboarding with aggressive decks. In the majority of situations you will be best served to keep sideboarding to a minimum when playing an aggro deck. Because aggressive decks normally require a combination of cards to win these concepts can effectively be applied to combo decks as well.
2. Surgical Extraction and Cranial Extraction Are Good
A linear combo deck revolving around a singular card may be susceptible to Extraction-type cards—in all other scenarios you should avoid adding these types of cards to your deck. It pains me to see people sideboard in Surgical Extraction against non-combo decks. Even against some combo decks, Memoricide is not effective—for example, Modern Splinter Twin combo. Twin decks are resilient against Memoricide because they have interchangeable, redundant combo pieces as well as the capability to win a normal game of Magic with cards like Vendilion Clique and Keranos, God of Storms. I can not tell you how many times I have had Surgical Extraction or Extirpate cast against my Delver deck in Legacy. Do you really think that removing Ponder from my library at the cost of a card from your hand benefits you? As a rule of thumb, try to not put Extraction-type cards in your deck.
3. Sideboarding Isn’t as Important in Limited
I notice players, including winning ones, neglect sideboarding in Limited completely. You may only have a few options, but that does mean that you should not exercise them.
Draft sideboard cards! Faced with a late choice between War Behemoth and Windstorm? War Behemoth is the definition of mediocre, whereas Windstorm fluctuates from unplayable to game-breaking. If you are on pace to have enough playables (22-24 cards), consider adding a niche sideboard option to your pool.
Sideboard lands out: There are a few factors that may lead me to remove land from my Limited decks. In a slow, attrition-based matchup drawing one fewer land may decide the game. If I am removing multiple expensive cards from my deck because of their ineffectiveness in a matchup I may as well remove a land. After winning a game it is likely that the opponent will choose to go first—being on the draw only adds to the allure of sideboarding out a land or two.
Switch colors: Switching colors entirely is mostly a consideration in Sealed deck. After you build your preferred Sealed Deck, attempt to build alternatives, perhaps with a friend’s opinion between rounds. If you play game one with a slow Sultai deck and then present a quick Boros deck for game two you may catch your opponent off-guard. For example your opponent may sideboard in Dutiful Return or Empty the Pits which would be effective against control but embarrassing against a fast deck. In order to physically do this operation within the tournament rules of sideboarding, (“a reasonable amount of time” from the end of the game to presenting a randomized deck for the next) you will need to have your alternate deck(s) prepared beforehand.
If you find yourself in a tight-knit damage race I strongly caution against sideboarding in niche cards and/or sideboarding out lands.
4. Always Bring in Your Specific Answers to the Opponent’s Cards
If your opponent is playing artifacts in his or her deck, should you sideboard in Shatter? It seems logical to think that if you have the option to interact with your opponent that you should—but it’s context-dependent. I already discussed how aggressive decks can’t afford to over-sideboard. You should be cautious of that trap regardless of what type of deck you are playing.
Let’s take the matchup of Abzan Midrange vs. Sultai Whip in Standard as an example.
You are playing Abzan and are intimidated by several of the threats in Sultai Whip. You are excited to sideboard as you have come prepared, bringing in 2 Erase, 3 Bile Blight, 2 Drown in Sorrow and, 2 End Hostilities—removing 4 Sylvan Caryatid, 2 Sorin, Solemn Visitor, 1 Wingmate Roc, 2 Elspeth, Sun’s Champion.
All of the cards you added are effective in specific circumstances but their addition came at the cost of multiple planeswalkers. Abzan Midrange is built upon a delicate balance of mana, answers, and threats. It is plausible that with this plan you will be able to stifle your opponent’s game plan for the majority of the game, but to what end? A deck like UW control from the previous Standard would have a density of answers this high because of the card advantage machine, Sphinx’s Revelation. Abzan does not have access to such a card. I would recommend keeping some or all of the planeswalkers instead of removal in order to finish the game once you have stabilized.
5. Sideboard Notes Are Good/Sideboard Notes Are Bad
Bringing prepared sideboard notes can be helpful or detrimental to different players. In an ideal world a player would have an open mind and be capable of diagnosing the optimal sideboard plan for each individual matchup even if it differs only slightly from the norm. Realistically, having a sideboard plan for popular, expected archetypes will benefit the majority of players. As you become more comfortable with your deck and a format, consider experimenting and diverging from your plans when you notice differences in your opponent’s specific deck/play-style.
I am happy to hear your perspective on the myths I discussed or any you have noticed, yourself.
Thank you for reading!
[Editor’s note: This article incorrectly referred to an old rule about the time allotted for sideboarding between games.]