That being said, being a sub 4:20 1600m runner w/ the requisite grades and test scores stands a better chance of getting in than does a generic valedictorian who does a bunch of student activities and sports, but isn't really a standout in any one activity.
The recent trends in elite college admissions show that schools are looking for students who stand out. Straight A's, high test scores, and a bunch of school activities don't cut it. Working a soup kitchen a Saturday morning every other week is nice, but starting and running your own is what the schools are looking for.
Still a crapshoot, but your odds will be better.