Top Pool Cleaner Robots

The Score Δ column only moves when a robot's own score moved. It is not a report on the week: rank position drifts whenever a neighbour moves, and publishing that as an arrow would be inventing movement. A robot that did not change reports how long it has sat where it sits, in days and then in weeks — so a score that settled last week is told apart from one nothing has touched in months. A trailing + means that streak runs back to the 30 July rescoring and is a floor, because no score can be compared across a change of formula.

Robots first sold before 2020 are held out of the standing. Robots with no recorded launch year stay in — an unknown year is not evidence of age, and treating missing data as old would quietly delete most of the catalogue.

Momentum belongs to the maker, not the robot. Every robot a maker sells moves together. Where we have no news signal at all the row says so in words rather than showing a zero — a zero would claim the company is quiet, when all we actually know is that we have not heard anything.

Makers are ranked on a separate board. A robot is never ranked against a company, so Top Pool Cleaner Companies is its own standing, built from each maker's robots in this category alone.

How this ranking is built — the factors behind the score, the year gate, how ties are ordered, and why Momentum is capped and bonus-only rather than averaged into the score.