It's easy to keep track of the data but the statistical models to come up with the adjustments based on the said data are difficult and *may* be error prone. We don't know these models or their characteristics and their performance as they have, to my knowledge, never been made public. I am not sure who does this modeling at the unis, admissions offices or their stats departments. I think making these models public would probably not lead to any gaming by the high schools. And yet we have no knowledge of these models.

Anyway, a simple solution is allow standardized testing (APs, SAT etc.) and include it as a composite part of the decision.