Most played cards in Red Deck Wins:

3 Decks
Rift Bolt
12 copies - 4 average
Incinerate
12 copies - 4 average
Greater Gargadon
10 copies - 3.33 average
Avalanche Riders
8 copies - 2.67 average
Mogg War Marshal
8 copies - 2.67 average
Keldon Marauders
8 copies - 2.67 average
Cryoclasm
8 copies - 2.67 average
Mogg Fanatic
8 copies - 2.67 average
Word of Seizing
7 copies - 2.33 average
Magus of the Scroll
6 copies - 2 average
Threaten
6 copies - 2 average
Scorched Rusalka
6 copies - 2 average
Ghitu Encampment
5 copies - 1.67 average
Sulfur Elemental
5 copies - 1.67 average
Seal of Fire
4 copies - 1.33 average
Char
4 copies - 1.33 average
Boom // Bust
4 copies - 1.33 average
Browbeat
4 copies - 1.33 average
Epochrasite
4 copies - 1.33 average
Guerrilla Tactics
4 copies - 1.33 average