Hey m rk
College predictor give results on the basis of many criteria like number of students appear in exam; difficulty level of exam; response of students after exam; and mainly on the previous year trends and marks v/s rank in last some years.
But it is not accurate it is just a prediction of rank / result it may vary ( because trend can be vary depending upon the students score and their hard work and this year you are getting 2 chance so it is most probably possible that statistics vary a lot and fluctuate.)
So be ready for every up and down.
Work hard and be in safe position.
Good luck