Most played cards in UW Control:

1 Decks
Warrant // Warden
4 copies - 4 average
Deputy of Detention
4 copies - 4 average
Opt
4 copies - 4 average
Dovin's Veto
4 copies - 4 average
Hallowed Fountain
4 copies - 4 average
Absorb
4 copies - 4 average
Glacial Fortress
4 copies - 4 average
Narset, Parter of Veils
3 copies - 3 average
Prison Realm
3 copies - 3 average
Ixalan's Binding
3 copies - 3 average
Teferi, Time Raveler
3 copies - 3 average
Teferi, Hero of Dominaria
2 copies - 2 average
Search for Azcanta
2 copies - 2 average
Chemister's Insight
2 copies - 2 average
Lyra Dawnbringer
2 copies - 2 average
Seal Away
2 copies - 2 average
Demystify
2 copies - 2 average
Elite Guardmage
2 copies - 2 average
Blast Zone
2 copies - 2 average
Settle the Wreckage
2 copies - 2 average