Since the day the first Magic player shuffled up a deck—or at least since Zak Dolan won the first major tournament at the 1994 Magic World Championship—competitors have sought to gain an edge on the field, and it didn't take long for them to realize that the battle begins long before Round 1.

For some, that means perfecting a draft strategy. For others, it's memorizing the best sideboard plans—once you know what you're up against. But there's nothing more important than deck selection.

Choose the wrong deck, and you'll find yourself fighting an uphill battle all weekend. Conversely, the right deck choice has carried many a first-timer to the Top 8 and, when it all comes together in the hands of the best, has created unforgettable legendary runs. For most of those runs, the path to beating the metagame was straightforward: teams (and "teams") of players would gather in a city two weeks before a major tournament, rent a house, and go to work pitting the top-performing decks of the previous weekend against each other and anything else they could imagine.

But there is no denying that the landscape of professional Magic changed drastically in recent years and that the move to virtual play during the pandemic has doubled down on that change. Rather than formats being solved over the course of months or even weeks, they're solved by millions of Arena players in a matter of hours. It's impossible to keep a breakout deck a secret, and with the rise of "big data" in Magic and the ever-growing popularity of aggregating tools and sites, it's harder than ever to gain that coveted pre-tournament advantage.

Even the greatest minds in the game make data a principal part of their effort. Here's how some of the game's top players are putting those lessons into action.

Digging Deep into the (Right) Data

With dozens of online events every month complete with metagame breakdowns and win rates just a few clicks away, players now spend nearly as much time studying the metagame as they do practicing it.

"There's so much data available, and there's a ton to be inferred from places like [MTG]Melee," explained Rivals League points leader Eli Kassis, who has spent much of the past year testing with Magic Pro League friends and teammates like LSV and Reid Duke.

"I miss doing the '[Pro Tour] House' thing, and I really hope those days come back; they were some of the best times of our lives."

"There is so much data available online now, and that data is vastly useful in cutting down the time we have to spend differentiating the different decks. Twitter is an excellent source, as is the Wizards of the Coast page with lists," Kassis said. "There's a lot of data out there, and we share it with each other as we come across it. There's so many viable decks nowadays that thoroughly testing them all isn't feasible, and the time save you get from looking at all the data available is the biggest benefit."

For those who may not have access to full testing teams, the proliferation of data and online tournaments has been a lifesaver. Lee Shi Tian, hovering around the middle of the MPL standings after a strong February Kaldheim League Weekend, faces more challenges than most and has credited online tournaments with helping him keep pace.

"For in-person events, I used to arrive a couple of days early to test with my teammates, but for digital tournaments, unfortunately the only MPL members in my time zone are me and some Japanese players, and there's a language barrier that exists," Lee explained. "Nowadays, I study the data in MTGMelee and Magic Online premium events. I tend to ignore the smaller events unless there is a breakout deck, but Magic Online events provide more insight into deck lists, while Melee has the tools to dig deep into particular matchups."

Win Rates Aren't Everything

But they are a good starting point. Trust, but verify. As any good professional Magic player in 2021 will readily admit, studying the data is merely the first step. Often there is no single dominant deck in a format, and success is more about predicting what the metagame will look like in a relatively small field, from a player's handful of League Weekend matches or even a just-over-200 player event like the Kaldheim Championship.

"Win rates are important, but not necessarily because they are accurate," said Seth Manfield, who enters the Kaldheim Championship just outside of the critical Top 4 of the MPL standings. "Sometimes win rates can change, but it establishes a perception that fellow competitors will have access to."

Lee Shi Tian went a step further.

"Looking at an overall win rate for a deck can provide a wrong image—top decks naturally have a higher win rate against non-tier decks that will pump up the overall win rates—so when I'm choosing a deck that suits the meta, I'm looking at the win rates against those top decks," he explained. "And then I'll study the gameplay and game plan for that particular matchup to make sure the data is reliable. My preparation has become more reading and less playing."

A perfect example is the February Kaldheim League Weekend. Entering the event, Mono-Red Aggro was posting solid numbers and was the second most played deck—but it was one of the worst performing of the weekend.

"Going in, it was posting such high win rates, but players fixed the matchup in their testing," Kassis recounted. "Everyone who stuck with it got crushed, while everyone who moved a step ahead did well."

Predicting the Field is Key

Change in competitive Magic has been continuous over the last 27 years, but at least one basic truth remains: the meta is always evolving and the "best decks" in a format are not necessarily the best decks for a given tournament.

While accurately predicting the metagame has always been an important—and difficult—task, its importance has been ever more heightened with the advent of the MPL and Rivals League. That means players are using the data not just to determine what the best decks might be, but what their opponents think the best deck might be. That leads to counter-pick—and even counter-counter-pick—strategies that demonstrate that even with access to all the data in the world, the cat-and-mouse game of one-upping the field continues to evolve.

When that all comes together, it can create legendary moments, like Luis Scott-Vargas's 16–0 run through the Swiss rounds at Pro Tour San Diego in 2010, or Team ChannelFireball breaking a format with CawBlade at Pro Tour Paris 2011, or Team East-West Bowl showing up with a brewer's dream in Blue-Red Eldrazi at Pro Tour Oath of the Gatewatch. In recent years, it's been the Czech House headlined by Stanislav Cifka and Ondřej Stráský that has been one step ahead of the MTG Arena metagame, brewing up format-changing decks like Kethis of the Hidden Hand combo.

"We follow the Melee and SCG results, but we try and verify them because there can be flukes where someone runs hot," Kassis explained. "Once we've narrowed down the top decks, we go a step further and try to predict what other people are going to play. People tend to follow certain people who are at the top of their game, so it's important to follow those players and read their articles because that impacts the metagame."

Don't Overthink It

With so much back-and-forth and (educated) guesswork that can go into selecting a deck, it may come as a surprise that some top players prefer to skip the data crunch and rely on the tried-and-true methods that have brought them success.

"You don't want to feel pressured into playing a deck," Manfield said. "You want to play something you are doing well with, and you don't want to play something that isn't in your comfort zone."

Manfield has made a career out of doing just that. He's had success with every archetype you can think of, but if given the choice, he will happily bring aggressive archetype he's comfortable with. Meanwhile, fellow MPL competitor Andrea Mengucci is upfront about the fact he won't sleeve up an aggro deck because he vastly prefers to pilot a control deck.

"People put too much trust in ladder play; I tend to not put too much trust in the win rates that show up in these events and need to see the matchup with my own eyes," he asserted. "Playing a deck [at Mythic rank] on MTG Arena is okay to identify if a deck is straight unplayable, but you can't use it to justify your deck choice. It's very important to read data with the eyes of someone who wants to discover something new and not just confirm what you already believed."

Mengucci is far from alone in his assessment.

Hot take : the amount of data available in Magic right now gives the biggest edge to people who don’t rely on it to understand what’s going on.

— J-E Depraz (@JEDepraz) February 5, 2021

Mengucci's approach has worked wonders for the 2019 Mythic Invitational champion. He's currently tied for sixth in the MPL standings and is primed to move close to a coveted Top 4 position with a strong Kaldheim Championship performance.

"Playing targeted testing against a teammate is still the only way to find out the true win percentage of a certain matchup," he said. "It's like staying informed nowadays: sure, you have to read the news, but you don't need to watch every single news show every day. My first concern is to enjoy my time while playing the event."

All the data and testing in the world matters right up until the event starts—and that's when everything changes again. The MPL and Rivals League players put their work to the test next at the Kaldheim Championship.

Get ready for all the action, broadcasting live March 26–28 at twitch.tv/magic!