<p>@Messiah, I am limiting this list to competitive mainstream American sports.</p>
<p>@keylyme: I agree that the two should be separated. Gymnastics is probably a tier one sport on an Olympic level. I probably lumped them in together since I saw a national cheerleading competition on ESPN2 and it seemed similar, but there is definitely a big difference.</p>
<p>@Brando: Swimming is in the first tier.</p>