As Anhydrite pointed out, applying for a major- except for universities where you have to select a “school” (such as arts, engineering, etc)- in the hopes of improving your chances of admission is not a good gambit. Most competitive schools won’t take it that seriously, because of things like this:
http://borderzine.com/2013/03/college-students-tend-to-change-majors-when-they-find-the-one-they-really-love/
http://thechoice.blogs.nytimes.com/2013/04/29/does-the-college-major-matter-not-really/?_r=0
http://dus.psu.edu/mentor/2013/06/disconnect-choosing-major/
https://www.■■■■■■■■■■■■/blog/declared-vs.-undeclared-which-is-better-on-a-college-application