501st Big Mike and Shiisaa have developed some revised rules for handling Unranked Summoners with regard to making balanced matches. (The previous rule had been to treat them as Golds.) I’ve copied Mike’s initial post below. More details are forthcoming.
In short, they did some tests comparing normal MMR to Factions rank, and found pretty strong correlations. If someone is unranked in Season 3, Season 4, and Season 5, they’ll have the Summoner queue up solo for a Normal match, and check the average MMR of the match through a third-party site. This allows them to assign the person an accurate effective rank without forcing them to do 10 placement matches.
We’ve had a bit of an problem concerning unranked players and having them play in Featured Matches and Tournaments, as they make it difficult to balance the teams. We’ve had a temporary rule in place that counted them as Gold rank, but we have been wanting to come up with a better, and more permanent, solution. We have finally come up with a new way to handle Unranked players and trying to balance them in Featured Matches. We have setup a way for the Matchstaff, which currently includes myself (501st Big Mike), insaiyanbacca, Shiisaa, XalkXolc, and Kwon Ri Sae, to determine an estimate of an unranked player’s MMR while they are in a game. So, from now on, for a Summoner who is unranked in Season 3, 4, and 5 to participate in Featured Matches and Tournaments, they will need to first contact a member of Matchstaff and have them determine an MMR and rank while they play a Normals game on Summoner’s Rift with a solo lobby (in other words, without invite friends to join the game with you); having friends join you for the game can throw off the MMR results. We are implementing this because we want to be able to have unranked players participate in the high stakes games of Featured Matches and Tournaments, but need a way to try and roughly balance the games by ranked tiers. This shouldn’t be too difficult to complete and we have listed a question on the Featured Matches sign up forms to see if any unranked players need to have Matchstaff determine their MMR and rank before the games this weekend.