Update 2/7/2013:
We’ve been keeping a very close watch on this week’s matchups and, despite our concerns regarding the recent population shifts, it seems that many of the games are quite competitive. At the same time we’ve been evaluating some possible changes to the math we use to calculate ratings. After examining a number of new methodologies for weighting the outcomes of matches we have found that our existing formulas already do pretty much what we want them to do. Certainly none of the candidates that we tried yielded better results.
In light of the strong community response to the idea of a WvW ratings reset, the results of our ratings formula investigations, and our data on the current matchups we have decided not to reset the WvW ratings at this time. All existing WvW ratings will be preserved and the rating calculation methodology will remain unchanged. Any existing mismatches should be corrected by the system in relatively short order. Now that there is less volatility in the player base for each world we expect the quality of matches to improve more quickly. This is both because the rating system is operating in a less unpredictable environment and because more stable teams tend to produce better results.
Thank you all for your feedback on this matter, and for your patience while we explored the various options. The community response was a key element in our decision making process.
Original Post:
In the run up to the end of free world transfers we saw large population changes as people settled in to their home servers. This means that the WvW teams being fielded by many of the worlds are now dramatically different. In recognition of this fact, and in light of the increased population stability that comes with paid transfers, we feel that this would be a good time to reset the ratings of all the servers. A reset at this point will allow the rating & ranking system to more quickly and correctly rate these (effectively) new WvW teams.
Here’s how the reset will work:
1) We’ll let the current matchup play out. Since free transfers were available during the first part of this matchup we don’t want it to count towards the new ratings.
2) When the matchup rolls over on Friday, February 1st we’ll post the final ratings & rankings. The new ordering will determine the groupings for the next matchup as usual.
3) After the new matchup has started on February 1st we’ll reset all the ratings (and deviation & volatility) behind the scenes.
Because every world will have reset ratings the system will treat the February 1st matchup as the first matchup and will calculate the ratings accordingly. The new ratings will then be calculated normally in the way that you’re already familiar with. We expect several weeks of volatility while the ratings settle down but we believe that it will ultimately yield a more correct result more quickly than letting the current ratings persist. That also means that the coming month or two will be a fantastic time to fight for your world’s place in the rankings!
Additionally, we’re taking advantage of the reset to revisit some of the math behind the ratings. I’ll have more to post on that once we’ve crunched some numbers and made some decisions.
ArenaNet Gameplay Programmer
(edited by Habib Loew.6239)
