I'll query the database to find the most recent tournament in Modern format.
The most recent tournament in the Modern format database is "Modern Challenge 32" held on September 28, 2025, from MTGO.
Sources: Data from MTGO tournament: Modern Challenge 32 (September 28, 2025).
https://www.mtgo.com/decklist/modern-challenge-32-2025-09-2812816543
Pro Tour Edge of Eternities in Atlanta, USA was held on September 26, 2025, making it one of the most recent tournaments in the database. This was a Modern format Pro Tour event hosted on Melee.
Sources: Data from Melee tournament: Pro Tour Edge of Eternities in Atlanta, USA (September 26, 2025).
https://melee.gg/Decklist/View/12b8999a-8ed4-4084-b82c-b36500ebf217
Pro Tour Edge of Eternities in Atlanta had 299 tournament entries and 2,370 total matches recorded in the database. This represents a substantial competitive event with comprehensive match data coverage.
Sources: Data from Melee tournament: Pro Tour Edge of Eternities in Atlanta, USA (September 26, 2025) with 299 entries and 2,370 matches.
https://melee.gg/Decklist/View/12b8999a-8ed4-4084-b82c-b36500ebf217
Based on the last 10 days of Modern tournament data, "unknown" archetype lists show an unusual pattern - they appear to be primarily Pre-Modern or Legacy cards rather than typical Modern cards. The most common cards include basic lands (Swamp in 46% of unknown decks), Swords to Plowshares (29%), Dark Ritual (25%), and Rishadan Port (25%). Other notable cards are Hypnotic Specter, Survival of the Fittest, and Exalted Angel - all cards that are not legal in Modern format.
This suggests these "unknown" entries may be misclassified tournament data from Pre-Modern or Legacy events that were incorrectly tagged as Modern format, or represent some form of data collection error. The presence of Wasteland, Rishadan Port, and other non-Modern-legal cards in what should be Modern tournament results indicates these decks don't represent actual Modern format gameplay.
Sources: Data from 4 tournaments (75% Melee, 25% MTGO) including Copa Pré-Modern Bil Dungeon and Pro Tour Edge of Eternities with unknown archetype entries.
https://melee.gg/Decklist/View/60bc500a-7444-4b4a-9e59-b366011fbaef
https://melee.gg/Decklist/View/29f1e1eb-cc1f-45a1-a15d-b36401510fea
https://melee.gg/Decklist/View/12b8999a-8ed4-4084-b82c-b36500ebf217
After removing the pre-modern tournaments, unknown archetype lists in Modern over the last 10 days show a mix of basic lands and some unusual card choices. The typical unknown deck contains basic lands (Forest in 60% of decks, Island in 60%, Swamp in 40%, Mountain in 40%) which suggests five-color or multicolor strategies.
The non-land cards are quite diverse and experimental: Sami's Curiosity appears in 40% of unknown decks, along with newer cards like Mechanozoa, Desculpting Blast, and various cards from recent sets. One deck appears to be running a Solitary Confinement combo strategy with Utopia Sprawl and Case of the Crimson Pulse. The presence of many singleton or two-of cards suggests these are highly experimental or fringe strategies that don't fit established archetype patterns.
With only 5 total unknown archetype decks across 2 tournaments, these represent very rare, likely homebrew strategies that tournament organizers couldn't classify into existing archetypes.
Sources: Data from 2 tournaments (50% Melee, 50% MTGO) from Pro Tour Edge of Eternities and Modern Challenge events.
https://melee.gg/Decklist/View/12b8999a-8ed4-4084-b82c-b36500ebf217
https://www.mtgo.com/decklist/modern-challenge-32-2025-09-2212815159