i wouldn't call one A- a failure.
i wouldn't even call a score that falls in the middle 50% range of accepted yale students a failure.
sure, you have a good chance. your ECs are not a problem--they come second after your grades, which are great.
apply to yale regular if you just wanna see if you can get in.
apply to yale EARLY if you really love the school, and feel ready to apply without your senior year grades.
it's as simple as that.
