How do you only run 21 mana sources? Oath usually has 23-25. That has to be terrible against Stax.
I started with a base of 23 mana sources, but the effect on my draws was terrible, slowing the deck down incrediably, since it was 99% land. I tried using Mana Crypt and Sol Ring coupled with the Mox, but again, the 2 mana makers were very unhelpful, being either one mana over or under what I needed.
I would consider:
-1 Fastbond/Crop Rotation
-1 Duress
+1 Island
+1 Flooded Strand/City of Brass
What would you suggest?