Each format has its own pool of available fixing of different power levels (meaning, the costs of the fixing lands relative to basics are of different magnitudes) but deckbuilders get to run what they believe to be the optimal number
The Frodo, Adventurous Hobbit display commander is printed with the foil-etched treatment on a thicker cardstockgreat for showing off your commander but not legal for play
Below, Im looking at the black spells and staples that control boards, fuel engines, and close games in Commander and other non-rotating formats
Number between parenthesis at right of a facet is the number of results of this facet
If they are running another color at all, it is only barely
Merrow Harbinger Tutors can be great, but they can leave you waiting for another turn to put anything onto the field