Denim, fit, and the three-pair problem
Ask any denim brand about bracketing and you will hear about the three-pair order: waist up, waist down, true size, shipped together, two coming back.
Denim earns this because fit is unforgiving and sizing is inconsistent across the industry. Customers have been trained by experience that the size on the label is a suggestion.
The cost is heavier than other categories because denim units are expensive to ship, slow to resell, and often come back creased or worn. A habitual three-pair customer can erase the margin of several honest ones.
The answer runs on both tracks: serious fit tooling for the honest uncertain shopper, and per customer scoring for the one who has ordered three pairs every month for a year. Same portal, different treatment, decided by their own history.