What the data actually measures
Most-played cards on RiftboundTracker are a count of which cards appear in submitted decklists across tracked tournaments. A card in 80% of lists means it appeared in 8 out of 10 submitted decks. This means it is community-trusted, not necessarily the most powerful card in the game. A card can be ubiquitous because it is the only reasonable option in its slot, not because it is exceptional. Open each top card and read the text to understand why the community trusts it.
Inclusion rate vs. average copies
Inclusion rate tells you breadth — how many decks use this card. Average copies tells you depth — how heavily each deck leans on it. A card with 70% inclusion and 1.2 average copies is a versatile one-of that many decks include for specific situations. A card with 60% inclusion and 2.8 average copies is a core piece that most decks play as a full playset. High inclusion with low copies is a flexible answer. High inclusion with high copies is a structural card in the deck.
How to use this without just copying
Open Most Played Cards for your legend is domain pair. Identify the top 15 by inclusion. For each card, open the Card page and read the text. Ask: does my deck is game plan need this effect? If yes, include it. If no, know why you are skipping it and test the difference. The goal is to understand why the community landed on those cards so you can make an informed choice about your own list.
Spotting bait cards
A bait card looks good in isolation but hurts consistency in practice. Signs of bait: it has high inclusion only in one specific legend, it is moderately expensive, it appears as a one-of, and the decklists that include it do not show strong conversion to top finishes. Cross-reference Most Played Cards with Tournament Results. Does the card actually help decks win, or is it just popular?