According to a new blog on the Guild Wars 2 site, the team has been looking at the way WvW matches have been playing and have discovered that the same realms were battling week after week. In an effort to shake things up and provide more variety in challenge, the team is introducing a brand new 'variance' formula.
The first values for this allowed your world’s matchup rating to be adjusted by as much as (deviation + 40), capped at 200. This fixed the staleness, and introduced a great deal more movement between ranks. We even saw some lower-rated worlds jump up the ranks now that they weren’t tied into the same matches week after week. For a good look at the history of world ranks, see Millenium’s charts for NA or EU (variance first began on June 7, or Week 23).
The new values allow for adjustments as much as (devation * 0.45 + 10), capped at 100. In both cases, the roll is plus-or-minus these values multiplied by a random real value in the range (-1,1).
Below, you’ll find four images showing estimated chances of each world facing the others under both the old and new values. Chances were calculated by matching up the various worlds 10,000 times, using current Glicko ratings. Chances were rounded and those under 1% omitted for readability.
Read the entire blog on the Guild Wars 2 site.