Currently some worlds, such as Crystal Desert, are stuck in what’s come to be referred to as “Glicko hell”. This is where a few worlds’ Glicko ratings drift off from the rest of the group, leaving a wide enough gap that those drifting away won’t be matched up against the rest.
To help prevent stale matchups, we’ll soon be able to artificially adjust Glicko ratings solely for the purpose of matchmaking.
For example, if we use this for NA’s lowest tier of worlds (T4), bumping them up to be just below T3’s ratings, they’ll have a decent chance of being shuffled into T3 during matchmaking. Given the ratings today, an adjustment we might make for July 29th could look something like:
T3:
- Maguuma: 1,838
- Sea of Sorrows: 1,777
- Stormbluff Isle: 1,767
T4:
- Crystal Desert: 1,512 (plus-185) = 1,697
- Sorrow’s Furnace: 1,398 (plus-130) = 1,528
- Darkhaven: 1,366 (plus-100) = 1,466
However, note that this artificial adjustment is invisible to anything but matchmaking. So if a T3 world doesn’t beat a T4 world significantly, the T4 world’s actual Glicko rating will increase more than usual, while the T3 world’s actual rating will decrease more than usual. Both worlds will also have increased deviation and volatility after. This is all because the T4 world’s lower rating means to Glicko “this world is expected to lose significantly to that T3 world”. So in an upset where this doesn’t happen, Glicko both makes larger adjustments to rating, since it was shown to need change, and increases deviation/volatility, to tell itself on the next round that these worlds haven’t settled into their most accurate rating yet.
EU’s lowest-rated world is still within its deviation of the lowest-rated world in the next tier up, making EU much less likely to receive artificial matchmaking adjustment on July 29th.