19 of 27 placements are statistically firm at this sample size — the other 8 sit close enough to a boundary that a slightly different sample could move them one tier. Hover a spec to see its figure and margin.
Tier boundaries are fixed and published: S is at least twice the median spec of its role, then 1.25×, 0.85× and 0.6×. They are not redrawn to fit each week's data, so a tier means the same thing every time you visit — and a tier can be empty when nothing reaches it.
Mythic+ only. A raid tier list was measured and dropped: the raid pool holds 88–201 players per spec, and at that size only 1 placement in 27 was statistically firm — a typical spec could sit in any of three tiers. Ranked PvP cannot be measured this way at all, because the ladder is already sorted by rating, so everyone scanned falls in the same narrow band. Raid and PvP spec distributions are still on the meta rankings page.