What constitutes a stronger opponent?

[Eugene]

I did an experiment and I believe it confirmed that the decision of weaker/stronger is made after the end of the game.

Do equal ranked opponent win/loss results count as 'weaker' or 'stronger'?

I tried one go of this just now, with two new accounts. The winner was deemed to have been stronger. This matches with my vague recollection that the decision (who is stronger) is made after the game. Note that it is extraordinarily rare for two equal ranked players to play each other. It’s the glicko number (rating) that counts for this, not the rounded rank (as smurph pointed out).