Most played cards in Izzet:

4 Decks
Force of Will
16 copies - 4 average
Volcanic Island
15 copies - 3.75 average
Shattering Spree
14 copies - 3.5 average
Pyroblast
13 copies - 3.25 average
Scalding Tarn
13 copies - 3.25 average
Lightning Bolt
12 copies - 3 average
Preordain
10 copies - 2.5 average
Flusterstorm
10 copies - 2.5 average
Ragavan, Nimble Pilferer
8 copies - 2 average
Force of Negation
8 copies - 2 average
Alpine Moon
8 copies - 2 average
Mindbreak Trap
7 copies - 1.75 average
Leyline of the Void
7 copies - 1.75 average
Dack Fayden
6 copies - 1.5 average
Dress Down
6 copies - 1.5 average
Wasteland
5 copies - 1.25 average
Blood Moon
5 copies - 1.25 average
Misty Rainforest
5 copies - 1.25 average
Flooded Strand
4 copies - 1 average
Pithing Needle
4 copies - 1 average