Most played cards in U/R Control:

1 Decks
Rewind
4 copies - 4 average
Shivan Reef
4 copies - 4 average
Spell Snare
4 copies - 4 average
Steam Vents
4 copies - 4 average
Mana Leak
4 copies - 4 average
Remand
4 copies - 4 average
Hinder
4 copies - 4 average
Compulsive Research
4 copies - 4 average
Electrolyze
4 copies - 4 average
Jushi Apprentice
3 copies - 3 average
Pyroclasm
3 copies - 3 average
Annex
3 copies - 3 average
Volcanic Hammer
3 copies - 3 average
Goblin Flectomancer
2 copies - 2 average
Repeal
2 copies - 2 average
Niv-Mizzet, the Firemind
2 copies - 2 average
Pithing Needle
2 copies - 2 average
Keiga, the Tide Star
2 copies - 2 average
Myojin of Infinite Rage
1 copies - 1 average
Shinka, the Bloodsoaked Keep
1 copies - 1 average