Positions in the same pool earn very different amounts of fees for their size, and that can be measured.
Measured over the days since each was last changed, the top fifth show which pairs and which ranges have been earning.
It is fees only, and it looks back: it says where liquidity earned, not where it will earn next.
A position changed only recently has no window to measure yet, so it is left out until it has one.
Very small positions are left out too, because a few cents of fees on a few dollars of liquidity says more about rounding than about skill.
The smart-money page here ranks the week's busiest pools this way and shows the pair and the range that those positions share.