From a theoretical standpoint, paper test scores should be a good indicator of CAT scores, but there's a big caveat here. The way in which we take a paper test in order to maximize a score is, in some ways, significantly different than the way in which we take a CAT to maximize a score. So - if you use all of the paper-test strategies to take a CAT, then you likely are NOT going to maximize your CAT score. In a practical sense, the paper tests may not be such a great indicator of your expected CAT score.

As such, I recommend to my students that they use the paper tests only as additional practice for individual problems (or small sets of problems), but not as full-length tests, because the actual process of taking a CAT is very different than the process of taking a paper test.