Most played cards in MUD:

1 Decks
City of Traitors
4 copies - 4 average
Ancient Tomb
4 copies - 4 average
Wasteland
4 copies - 4 average
Rishadan Port
4 copies - 4 average
Mishra's Factory
4 copies - 4 average
Thran Dynamo
4 copies - 4 average
Karn, Silver Golem
4 copies - 4 average
Urza's Bauble
4 copies - 4 average
Mind Stone
4 copies - 4 average
Metalworker
4 copies - 4 average
Tangle Wire
4 copies - 4 average
Mishra's Helix
4 copies - 4 average
Masticore
4 copies - 4 average
Tranquility
3 copies - 3 average
Stalking Stones
2 copies - 2 average
Powder Keg
2 copies - 2 average