User blog comment:Commander Marko/The advantage of Duo Queue/@comment-4888212-20130922014427/@comment-13014780-20130922160423

"Recently started Ranked (Duo) and my higher-ranked partner ends up last-pick while I am often first; that hidden MMR is quite wonky."

What I've heard, no idea if it's correct, is that the party leader has a much higher chance to be first pick than those invited to the party.