Dear SuperFanMike : Your profile has offered three points : your GPA (is it in the top 10% of your current High School class), an SAT score (right around the top quartile for BC), and a three sport captain's role. Let's offer just some of the other items to consider : music, arts, volunteerism, jobs, community leadership, school leadership (beyond captain's role), clubs, AP course work, business experience, internships, and a host of other topics.
Worrying as to whether CSOM is more competitive than CAS is not a useful expenditure of your time since you are only considering CSOM. (In fact, the difference is statistically insignificant and certainly does not hold the test of numbers over the long haul.)
Continue pressing the envelope on academics and your overall rounded profile or demonstrating a distince passion in one area. Be sure that you are able to demonstrate why you add to the Boston College campus fabric in your essays and application. To answer this question, it is often best to have visited the campus at least once.