To the extent that SAT scores are used to select which students are admitted to which colleges, you remove any predictive relationship between SAT scores and gr

To the extent that SAT scores are used to select which students are admitted to which colleges, you remove any predictive relationship between SAT scores and grades. I.e. even if SAT scores were perfectly predictive of "college performance" in the abstract, if there were N possible scores on the SAT and exactly N colleges, each of which accepted all students with one specific score, then SAT scores would be completely uncorrelated to college grades. This is an arbitrarily contrived example, but the same principle holds true in the real world.