50% of all picks in OfA belong to 6 champs
If the following statistics are accurate (and they're based on 170,000 games, so I would say yes):
http://www.manaless.com/2015/10/one-for-all-statistics-2015.html
So for those of you saying there's PLENTY of "variety" in OfA, you got lucky for a few games. These results reflect my own experience. I must have had 3 Darius games yesterday, followed by a Darius vs Darius game, followed by another Darius game. Of the games in my current match history, two thirds of them are declared-broken champs I see constantly. Look, I don't mind if a large portion of players want to spam the same champs every game. Just as long as I don't ALSO have to spam the same champs, because I'm stuck with spammers on my team every game due to matchmaking's total randomness.
If 6 people in a game of 10 all want to play an overused "broken" OfA champ, but 3 of them are on one team, and 3 are on the other, should the remaining 4 players really have to play their billionth game of DarDar dunking, when all you need to do is put 5 spammers on one team, and the 4 players who want some breathing room on the other team? Yes, one player may not get what they want, but that's better than FOUR players not getting what they want on a repeat basis. We really need a queue where you specify your champ preferences or champ category preferences for matching.
##OfA-Teambuilder
P.S. I put "broken" in quotation, because there's really no correlation between popularity and winrate with these champs. Yes, Darius is up there at 70%, but some champs with winrates just as high have near-zero popularity (Jax, Nocturne, Nasus, Galio, all champs who I haven't had a chance to try out or even SEE on OfA yet after a ton of games). So please don't make dumb comments such as "who wants to play a crap champ and get owned by heimer every game?" My first OfA game this year, my team demolished Darius as Soraka, a champ with both a crap popularity AND win rate. Next game as soraka, nobody seemed to understand the pair-heal synergy and they just kept conserving their health in lane at full mana (facepalm).
Even some high-popularity champs fail hard. But even if it's a low-pop champ failing, it's generally due to people having a lack of familiarity with the champ, or heck, even trying to play the champ effectively in OfA teambuild (I get matched with a lot of people who don't really try with a champ that they don't really like, and spend half the game whining about the pick). Which is why I'd like to be matched with the small minority that a) WANTS to play a low-pop champ and b) ergo, likely knows how to play the champ, or will at least try to make something of the champs self-synergies. If OfA had a Teambuilder, I bet you'd see the winrates flip on their heads. At which point, heck, even the same-pick-spammers would probably add a little variety to their preferences, and this gamemode would become a lot cooler.