Most played cards in Smog Combo:

1 Decks
Brainstorm
4 copies - 4 average
Ponder
4 copies - 4 average
Preordain
4 copies - 4 average
Polluted Delta
4 copies - 4 average
Thoughtseize
4 copies - 4 average
Summoner's Pact
4 copies - 4 average
Witherbloom Command
4 copies - 4 average
Dark Ritual
4 copies - 4 average
Lotus Petal
4 copies - 4 average
Misty Rainforest
4 copies - 4 average
Chain of Smog
4 copies - 4 average
Abrupt Decay
3 copies - 3 average
Defense Grid
3 copies - 3 average
Carpet of Flowers
3 copies - 3 average
Surgical Extraction
2 copies - 2 average
Flusterstorm
2 copies - 2 average
Sylvan Safekeeper
2 copies - 2 average
Lim-Dûl's Vault
2 copies - 2 average
Tropical Island
2 copies - 2 average
Underground Sea
2 copies - 2 average