I’m not a believer in chance threads. They’re usually answered by other kids, who have no better an idea than you of your real odds.
But I’m the mom of 3 teens, of of whom is a high school senior. She’s gotten two of those thin envelopes in the past months, one from her number 1 choice school… and yes, she applied knowing it was a reach.
Here, in a nutshell, is my advice: http://talk.collegeconfidential.com/college-admissions/2047371-so-you-didnt-get-in-p1.html
Good luck!!