It doesn't matter if you lose or win. If you do well individually in a large percentage of your losses, your medal gets upgraded. At least, that's what happened to me. I kept a steady W-L-W-L streak, and definitely did not climb the 180 or however much MMR required to progress to next medal, but I just got upgraded from Archon 4 to 5. Plausible?
It doesn't matter if you lose or win. If you do well individually in a large percentage of your losses, your medal gets upgraded. At least, that's what happened to me. I kept a steady W-L-W-L streak, and definitely did not climb the 180 or however much MMR required to progress to next medal, but I just got upgraded from Archon 4 to 5. Plausible?