Pioneer is the youngest of Magic's Constructed formats, and this weekend marks the first time it comes to the big stage. Prior results, mostly from Magic Online, have given us some ideas of what to expect. But the inaugural events of the Players Tour paint a more complete picture, as hundreds of the game's best and brightest put their most formidable deck designs to the test. Not to mention that the recent addition of Theros Beyond Death has challenged, or inverted, some of the truths about Pioneer previously posited.

Let's delve into the data from Brussels!

Archetype # % Mono-Black Aggro 53 13.8% Dimir Inverter 47 12.2% Azorius Control 37 9.6% Niv to Light 35 9.1% Azorius Spirits 23 6.0% Izzet Ensoul 21 5.5% Mono-White Devotion 14 3.6% Simic Ramp 14 3.6% Mono-Red Aggro 12 3.1% Big Red 11 2.9% Mono-Green Ramp 11 2.9% Lotus Breach 9 2.3% Bant Spirits 7 1.8% Simic Delirium 7 1.8% Izzet Phoenix 6 1.6% Mono-Black Vampires 6 1.6% Soulflayer 6 1.6% Sultai Delirium 6 1.6% Heliod Company 5 1.3% Golgari Stompy 4 1.0% Mono-White Lifegain 4 1.0% Dimir Control 3 0.8% Hardened Scales 3 0.8% Kethis Combo 3 0.8% Lotus Storm 3 0.8% Mono-Blue Devotion 3 0.8% Mono-Green Stompy 3 0.8% Others 23 6.0% Total 384 100.0%

Pioneer may be a whole new world, but the time-tested division into aggro, combo, and control still applies. In fact, the three most popular decks neatly fall into place to give one example of each. Mono-Black Aggro has been among Pioneer's top strategies since the format's inception, and it accounts for a whopping 13.8% of the Brussels field. Azorius Control has been a mainstay of all of Magic since time immemorial, and its Pioneer incarnation goes into the tournament as the third most played archetype, at 9.6%. Arguably the biggest story deck-wise concerns the combo aspect of the trifecta ...

Introducing Inverter Combo, the Second Most Popular Deck

During Theros Beyond Death previews one card caught everyone's attention because of its combo potential: Heliod, Sun-Crowned, which enables Walking Ballista to shoot infinite damage. However, while Heliod is part of the Pioneer metagame, another devotion card from the set ended up far more relevant. The new premier combo deck of the format uses delve spells such as Dig Through Time to clear the graveyard, then Inverter of Truth to leave but a few cards in the library, and wins via Thassa's Oracle.

A similar line of play had been possible before, with Jace, Wielder of Mysteries. But Thassa's Oracle is what brought the archetype to the forefront. Adding a second and cheaper win condition has turned the deck from meme to monster. 12.2% of all competitors in Brussels registered Inverter of Truth, but 33.3% of MPL members in attendance did.

Among them, Piotr Głogowski was the most vocal and public proponent of the deck. Fresh off a victory at Mythic Championship VII, Głogowski's endorsement probably pushed even more people onto the deck.

Every Color and Kind of Strategy Represented

Whether you enjoy multicolor madness or the simplicity of a monocolored build, Pioneer does have just the deck for you. Right after the big three, Niv-Mizzet Reborn perches at 9.1%, and the aforementioned Heliod, Sun-Crowned found a place in Mono-White Devotion, the seventh most played deck. If you prefer the tempo-oriented playstyle of aggro-control, Azorius and Bant Spirits together make up 7.8% of the field. And ramp decks, some just green and some with blue, account for a total of 6.5%.

Overall, the metagame presents a lot of variety. Only Mono-Black Aggro and Dimir Inverter crossed the ten-percent threshold, and only Azorius as well as Niv-Mizzet came close. After that, seventeen different deck types all sit at metagame shares between 1% and 6%. In total, the table above lists 27!

And that's not even going into the "Others" category. This includes two copies each of Dredgeless Dredge, Jeskai Ascendancy, Orzhov Vampires, Rakdos Dragons, and Rakdos Midrange, as well as eighteen decks with but a single copy in the running. To name but a few: Boros Feather, Esper Dance, Goblins, Izzet Emerge, Jeskai Fires, Jund Sacrifice, Mono-White Humans, Orzhov Eldrazi, Possibility Storm ...

An Esper Slant Among the Most Played Cards

Looking at the full 384 decklists, the 30 most played cards reveal a slight preference for the black, blue, and white spectrum of the color pie. But all of the colors are represented, and all five basic lands earned a spot among the top seven maindeck inclusions. That Thoughtseize and Fatal Push clock in as the most popular nonland cards shouldn't surprise anybody at this point.

Thassa's Oracle and Uro, Titan of Nature's Wrath make for the biggest additions from Theros Beyond Death, followed at some distance by 100 copies of Heliod, Sun-Crowned.

Card Total Copies Maindeck Copies Sideboard Copies Swamp 1120 1120 0 Island 903 903 0 Thoughtseize 624 521 103 Plains 608 608 0 Mystical Dispute 601 17 584 Fatal Push 553 486 67 Mountain 507 507 0 Forest 472 472 0 Fabled Passage 422 422 0 Mutavault 418 416 2 Opt 368 368 0 Hallowed Fountain 326 326 0 Dig Through Time 321 321 0 Murderous Rider // Swift End 279 274 5 Rest in Peace 278 0 278 Glacial Fortress 275 275 0 Teferi, Time Raveler 273 253 20 Watery Grave 260 260 0 Knight of the Ebon Legion 244 244 0 Castle Locthwain 243 243 0 Scrapheap Scrounger 241 241 0 Censor 216 216 0 Bloodsoaked Champion 215 215 0 Drowned Catacomb 210 210 0 Thassa's Oracle 204 204 0 Inverter of Truth 196 189 7 Breeding Pool 195 195 0 Uro, Titan of Nature's Wrath 194 194 0 Supreme Verdict 188 178 10 Wild Slash 182 178 4

The stage is set, the battle lines are drawn. Now it's all on the actual games to decide what ascends to the heavens and what plummets to the underworld. Check back tomorrow to find out which decks make the cut to Day 2!