USA Ultimate developed their current College ranking system to replace the RRI system. It is not clear what weakness in RRI was being addressed with this change.
With the USA Ultimate College system, ratings are re-calculated on a daily basis, taking into account the strength of each team's schedule. For example, if your first game was a loss to a low-ranked team who later prove themselves to have been initially under-estimated, the penalty for that loss will be reduced as the season progresses.
As of 2014, USA Ultimate is using an updated version of this algorithm for both the College and Club series, available here as "USA Ultimate Rankings v2".
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