EDITORIAL NOTE First 11th-edition data is live — the ELO ladder reset with it ›
EDITORIAL NOTE

First 11th-edition data is here — and the ELO ladder resets with it, every player back to a clean slate. The opening tournament results are in and the Strength Index is beginning to take shape across its signals, but a new edition takes time to read: expect weeks, likely months, before the numbers can support real conclusions. An early signal, not a verdict.

WILSON INTERVAL

CI EXPLORER

How wide is the uncertainty around that win rate?

A reported win rate is a measurement, not the true rate. The Wilson interval gives the range of values that are consistent with the data at a stated confidence level. The tighter the range, the more the sample supports the point estimate. Slide the controls below to explore.

CONTROLS
VISUALIZATION
TAKEAWAY
WHY WILSON RATHER THAN WALD?

Wilson behaves well at small N and at proportions near 0 or 1, where the more familiar Wald (normal-approximation) interval becomes misleading. 95% is the conventional confidence level; this tool uses it throughout.