Most played cards in UW Control:

1 Decks
Field of Ruin
4 copies - 4 average
Teferi, Hero of Dominaria
4 copies - 4 average
Glacial Fortress
4 copies - 4 average
Meandering River
4 copies - 4 average
Chemister's Insight
4 copies - 4 average
Sinister Sabotage
4 copies - 4 average
Seal Away
3 copies - 3 average
Settle the Wreckage
3 copies - 3 average
History of Benalia
3 copies - 3 average
Essence Scatter
3 copies - 3 average
Negate
3 copies - 3 average
Shield Mare
2 copies - 2 average
Lyra Dawnbringer
2 copies - 2 average
Baffling End
2 copies - 2 average
Memorial to Genius
2 copies - 2 average
Search for Azcanta
2 copies - 2 average
Devious Cover-Up
2 copies - 2 average
Syncopate
2 copies - 2 average
Disdainful Stroke
2 copies - 2 average
Cleansing Nova
2 copies - 2 average