Most played cards in Red Deck Wins:

1 Decks
Bloodstained Mire
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Price of Progress
4 copies - 4 average
Wooded Foothills
4 copies - 4 average
Lava Spike
4 copies - 4 average
Goblin Guide
4 copies - 4 average
Eidolon of the Great Revel
4 copies - 4 average
Monastery Swiftspear
4 copies - 4 average
Chain Lightning
4 copies - 4 average
Smash to Smithereens
3 copies - 3 average
Searing Blaze
3 copies - 3 average
Rift Bolt
3 copies - 3 average
Fireblast
3 copies - 3 average
Relic of Progenitus
2 copies - 2 average
Pyrostatic Pillar
2 copies - 2 average
Searing Blood
2 copies - 2 average
Grim Lavamancer
2 copies - 2 average
Pyroblast
2 copies - 2 average
Deflecting Palm
2 copies - 2 average
Faerie Macabre
2 copies - 2 average