Sideboarding is an art form in and of itself.
Along with your 60-card main deck, you get to bring your fifteen-card sideboard to the tournament table. And while most people playtest just using their main decks, that's actually a little inaccurate: statistically, at least half of your games in a tournament will be played using your sideboard. And assuming you aren't on fire and winning every game you play in a best-two-out-of-three match, you will always play more sideboarded games than purely main-deck games.
Your sideboard can be one of your greatest weapons—or, if used incorrectly, one of the easiest ways to sabotage yourself.
I could write many articles on properly using a sideboard. (And I probably will.) Today, I want to take a look at one particular element in depth: sideboarding the appropriate number of cards for a matchup in Standard. (This can be applicable in other formats too, but formats older than Standard do often break these rules because of the strength of sideboard cards and how many hate cards you might need for a certain deck.)
Ready? Let's jump into it!
The Sideboard Resource
Your sideboard is a limited resource. Because you're allowed only fifteen cards, you need to make every card in your sideboard count and be meaningful. If you end up with five cards in your sideboard that you never use, that's a full third of your sideboard you've lost that could have fundamentally turned a matchup.
That means you really need to budget how you're using your cards. For example, if you sideboard all fifteen cards in one matchup, and now you always win that matchup, well, great—but even in a Standard metagame dominated by one deck, you're unlikely to face that deck every round. You probably want some sideboard options for other decks.
If you could build a sideboard completely omnisciently, your goal would be to have exactly enough cards for each matchup so that you win without sideboarding a single extraneous additional card. And while we may not be omniscient, we can at least try and get close.
There are a few different ways to measure if you're sideboarding appropriately or not. Here are the three main ways I tend to try to make sure I'm putting the right number of cards for a matchup in my sideboard.
1. Make Sure You Have Enough Cards to Take Out
Let's say there's a matchup you really want to improve. So, you put seven cards in your sideboard that you want to bring in for the matchup. Great! Now you can crush them. You go to the tournament, excited to have an array of options.
You sit down against the deck you're sideboarding all these cards to beat. You play Game 1. You go to sideboard before Game 2...only to realize you're having trouble figuring out what to take out! You end up having to take out cards that are also good in the matchup to fit in your sideboard cards.
This is a classic sideboarding error. With only fifteen valuable slots, sideboarding should primarily be used to upgrade your deck, not just side-grade it.
For example, let's say you're playing a blue-black-red (Grixis) control deck much like the deck used to win Pro Tour Kaladesh in current Standard against an aggressive deck. You want to bring in a bunch of removal spells to fight off their starts. The first few cuts are easy, removing counterspells. But then, you find you're having to remove cards like Harnessed Lightning just to make room for more efficient removal spells! What are you accomplishing here?
Yes, your deck might be slightly more efficient with this other removal spell—but it's not that much of an upgrade over what you already had. I'd far rather use that slot for a different matchup that needs the help than make a small boost to this one.
Additionally, you run the major risk of diluting your deck. I see this happen all the time, especially in aggressive decks, as you start cutting creatures for reactive cards and you majorly slow yourself down. There's a core your deck needs to function, and if you start eating into that core then it can impact how your deck performs in a major way.
Something I do when I built my sideboards is just figure out how I'm going to sideboard in every matchup. If it seems like I'm taking out cards I'd want to keep in, then I usually rework my sideboard and give some of those spaces to other cards.
I highly recommend thinking about how you generally want to sideboard in each matchup before you finalize your fifteen.
2. Make Sure Your Sideboarding Matches a Deck's Prevalence
You hate losing to Aetherworks Marvel. So, you carefully test the matchup. You fill your sideboard with plenty of cards for it. You have more than enough cards to take out. You're ready to go. Those Marvel decks don't stand a chance.
You go to a tournament. And, just like you drew it up, you smash Aetherworks Marvel. The problem? You only play against Marvel once in the event!
What happened here?
While it's important that you sideboard the right number of cards, it's also important that you make sure you're sideboarding appropriately based on what you expect. If you don't foresee many of a certain deck showing up, then you can dedicate fewer sideboard slots to it.
Often, what I do is start by measuring out which decks I think will be the most popular, and (going back to point #1) making sure I have the right number of sideboard cards for each of them based on what I can take out. Then, with the remaining slots, I apportion some cards to the less popular matchups.
Additionally, sometimes you can get cards that carry over and can be used in multiple matchups. For example, counterspells are good in the control mirror and also good against Marvel. Finding ways to fight less popular decks using multipurpose cards you already want for other matchups is a great way to ensure your sideboard is well-rounded. That way, you can attack a wide variety of decks while still being focused on a few main ones.
3. Make Sure You Need the Help in This Matchup
Sideboarding is there to help swing unfavorable matchups and to stay toe-to-toe with your opponent as they sideboard. However, what you should definitely avoid is sideboarding a ton of cards for a matchup that's already in your favor.
Now let's say you're playing the aforementioned blue-black-red control deck against Aetherworks Marvel. That's a pretty favorable matchup in Game 1. Now, when you go to sideboarding, the Marvel deck is likely going to bring in plenty of cards for you—and you certainly shouldn't bring in nothing.
However, you also probably shouldn't be bringing in a ton of cards.
For one, you likely just don't have that many cards you want to take out if you were already favored in the first game (as covered earlier.)
Secondly, you don't need a drastic amount of help. Remember: you want to sideboard exactly enough cards for the matchup so that you win, not too many. If you just sideboard in a few cards here, that's okay. Yes, there's always the chance your opponent could have a huge ten card sideboard meant to punish you—but most of the time they'll have just a few cards and, as long as you sideboard in a few more cards to push you over the top, you'll usually be fine.
Staying on Board
Building a Standard sideboard can be a tricky thing, and hopefully this gives you some tools and direction to go forth and work on yours. Sideboard help is one of the most common requests I receive.
There's a lot more to talk about with sideboarding, and this is just the tip of the iceberg. So, if you enjoyed this, please let me know and I can cover more on sideboarding in the future. (Or not, if the opposite is true.)
Talk with you again next week! Until then, may you sideboard exactly the number of cards you need to.