Blizzard has posted an overview of the new Arena matchmaking system, detailing some of the reasons and philosophy behind the new system.

We recently introduced a new Arena matchmaking system with the intent of better matching up players against opponents of similar skill level, and to address potential abuses under the old system. We realize that many players have questions regarding the new system, and as such, we would like to provide more insight into the new matchmaking system.

• First and foremost, the primary goal of the new Arena matchmaking system is to match players against opponents of similar skill, regardless of your or your opponents’ team rating. This means that once an estimated skill level is determined, you will more likely be matched against other players of a similar skill level. Please note that the estimated skill level is constantly being evaluated and will adjust based on each team’s continual performance. Ratings that are won or lost also take into account skill level, so that you will not suffer a high penalty if you lose against a team that is much better than their actual team rating.
• Another important aspect of this new Arena matchmaking system is a smaller range of maximum rating that can be won or lost. Because of the differences between how the new system assigns rating points at the end of a match, we are still tweaking rating gain versus loss per match to improve the experience.
• If you were previously ranked with a high skill level and decide to create a new team, it should now be much easier to reach your team’s correct rating. This ensures that players will not feel penalized for moving between teams, and high ranked teams will not feel penalized for trying out new players without much risk to the team rating itself.
• Finally, the core and fundamental reason for the new Arena matchmaking system is for players to participate in Arena games that are fun. We feel that with this new system, higher ranked players will most likely find the challenges that they seek, newer players will no longer feel that Arenas are closed to them, and players will not feel as penalized for trying new things in the Arenas.

Read more here.