I’m typically a very good student, but after taking practice tests for SAT/ACT I don’t think my scores are likely to show my academic abilities well (frankly just not a very good test taker). So what do the test optional colleges want to see (of course knowing that GPA is likely a major factor with many of them.
They want to be able to admit “hooked” students (athletes, URMs, children of big donors, etc.) who may have lower scores, but without taking a hit to their reported averages (or US News rankings). They want to have their cake and eat it too.
That is, the policy IMO is meant to benefit the college more than the student with modest scores. If you apply without submitting scores, naturally they’ll assume your scores are low. So, presumably you’ll need to be outstanding in some other area to compensate. Hard to say what that might be if it’s not one of the usual hooks. Excellence in some interesting extracurricular, maybe. Evidence of outstanding leadership potential, maybe. Unusually good essays, maybe. If you’re applying for Fall 18, it’s a little late to do much about any of these but the essays.
I would assume that your chances are not much better than they would be without the TO policy, if you submitted your scores. But maybe I’m being too cynical, so if you like the college give it a shot. Some TO colleges may be facing a relative shortage of high-scoring applicants, therefore they really would be taking students with lower scores than they’d prefer. So just do your best to prepare a good application, submit it on time, and be sure you also apply to less selective safety/target schools in case this one doesn’t work out.
What are they looking for? Check their websites, and see what they have to say for themselves. But generally speaking, they are looking for excellent grades, strong essays, and strong letters of recommendation.
If you have always been a poor test-taker relative to your classroom performance, take some time to rule out test-based anxiety, poor test-taking strategies, and learning differences in the slow processing/dyslexia family. Each of those has a different fix or accommodation, and given the number of tests you will face in college it is a good idea to sort this out while you are still in high school.