Most played cards in Grixis Pyromancer:

1 Decks
Polluted Delta
4 copies - 4 average
Serum Visions
4 copies - 4 average
Fatal Push
4 copies - 4 average
Scalding Tarn
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Delver of Secrets
4 copies - 4 average
Snapcaster Mage
4 copies - 4 average
Thought Scour
4 copies - 4 average
Spell Snare
3 copies - 3 average
Surgical Extraction
3 copies - 3 average
Tasigur, the Golden Fang
3 copies - 3 average
Engineered Explosives
2 copies - 2 average
Negate
2 copies - 2 average
Mana Leak
2 copies - 2 average
Murderous Cut
2 copies - 2 average
Kolaghan's Command
2 copies - 2 average
Young Pyromancer
2 copies - 2 average
Spirebluff Canal
2 copies - 2 average
Steam Vents
2 copies - 2 average
Gurmag Angler
1 copies - 1 average