Second, sometimes a deck that can run a thing doesn't need to or shouldn't, because it's contrary to the goals of the deck or doesn't match the plan
This allows it to gain back that counter
How many rares are in a play booster box
There's an excellent data analysis post by u/IamMandrell on reddit, analyzing trophy decks (that's to say, only looking at decks that reached 7 wins)
Brawl Not Legal Vintage Not Legal Timeless Not Legal Commander Not Legal Pauper Not Legal Oathbreaker Not Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Metagamer: You can find more information on the latest Mythic Championship, including decklists, at MTGEsports.com
Historic Horizons utilizes its digital-only nature beyond these three recurring mechanics as well, with WotC saying it makes it possible to print cards with rules that wouldnt fit in a paper frame