My friend (Sage) is Radiant, I myself am currently Imm1. I finished a game with almost every stat better; kills, less deaths, higher econ, higher combat score etc. However I only received 2 up arrows whereas my radiant friend (playing at a rank he is expected to play at) received 3 up arrows.

Any ideas why?
Maybe first bloods?

https://imgur.com/a/dYmTMTW