Every champion on BestBuilds.LOL gets a tier from S+ down to D. Those letters aren’t hand-picked and they aren’t based on a designer’s vibe — they come out of a small statistical model applied to the current sample of games. This post walks through what actually goes into that letter.
The three inputs
For every champion (or, on the tier-list page, every champion + role combination) we compute three numbers from the last patch window:
- Win rate — how often that champion’s team wins.
- Pick rate — what share of games the champion appears in.
- Ban rate — how often the champion is banned in champ select.
Nothing exotic — the same three signals every stats site uses. What matters is how we combine them.
Why raw win rate is a bad tier signal
If we just sorted by win rate, obscure counter-picks and one-tricks would dominate the top of the list. A 55% win-rate champion picked in 0.4% of games isn’t strong — the sample is tiny and heavily self-selected (only people who main it are playing it). Meanwhile a 51% pick-or-ban menace with 30% presence is genuinely warping the meta.
Z-scores, in plain English
For each of the three inputs we compute a z-score: how many standard deviations above or below the roster average that champion is. Then we add the three z-scores into a single strength score, weighted a little more toward win rate. That gives us a distribution where the average champion sits around zero, top champions score around +1.5 to +2.5, and bottom champions score around -1.5.
The tiers are just buckets on that score:
- S+ — top ~3% (extreme outliers, priority ban/pick)
- S — next ~10%
- A — next ~20%
- B — middle ~35% (fine, no strong opinion)
- C — next ~20%
- D — bottom ~12% (avoid blind pick)
What the tier does NOT tell you
A tier is a rough summary. It doesn’t know your rank, your champion pool, or the matchup you’re about to blind-pick into. A B-tier champion you main will out-perform an S+ champion you’ve played twice. Use the tier list to know what’s strong right now, then use the individual champion pages to check whether it fits your playstyle.