Incoming links: Bimatrix game
Magic: The Gathering meta-based deck choice is a bimatrix game Updated 2024-12-15 +Created 1970-01-01
Ciro had initially Googled for the "4-card limit thought experiment" but he reached: www.channelfireball.com/articles/what-if-the-4-card-limit-was-abolished-in-modern/ "What if the 4-Card Limit Was Abolished in Modern?" by Frank Karsten (2018) and was much more pleased with the mathematical result. Like-minded people.
That links to www.channelfireball.com/articles/what-if-the-4-card-limit-was-abolished-in-modern/ the related article: "The Mythic Invitational's Duo Standard Format Game Theory Optimized" by Frank Karsten (2019) which explains well how Nash equilibrium is naturally reached: if there is any imbalance, someone can take advantage of it, and then it rebalances. Therefore once you've calculated the equilibrium, your best course of action is to pick a deck at random from a list of possible winners.
Of course, part of the beauty of Magic is that we can never really know the full matrix since deck choice is basically infinite. But at the very least it could give good archetype results.