Most played cards in Ninjas:

145 Decks
Brainstorm
580 copies - 4 average
Force of Will
577 copies - 3.98 average
Polluted Delta
576 copies - 3.97 average
Ornithopter
558 copies - 3.85 average
Ingenious Infiltrator
556 copies - 3.83 average
Ponder
528 copies - 3.64 average
Retrofitter Foundry
504 copies - 3.48 average
Changeling Outcast
496 copies - 3.42 average
Yuriko, the Tiger's Shadow
458 copies - 3.16 average
Prismatic Vista
406 copies - 2.8 average
Fatal Push
338 copies - 2.33 average
Daze
322 copies - 2.22 average
Thoughtseize
318 copies - 2.19 average
Plague Engineer
309 copies - 2.13 average
Underground Sea
289 copies - 1.99 average
Leyline of the Void
248 copies - 1.71 average
Baleful Strix
237 copies - 1.63 average
Snow-Covered Island
235 copies - 1.62 average
Force of Negation
204 copies - 1.41 average
Surgical Extraction
178 copies - 1.23 average