I know nothing about sports and I am using "emo" as a broad term.
Please be nice.
American Football is probably the most well known of these bands. The legend of their name is "The band got their name from a poster that Lamos' girlfriend had spotted. The poster read, "Come see American Football, the most overpaid athletes in the world."
Could is be as simple as that? A Poster in 1998 started it all?
Karate is an American band, formed in Boston, Massachusetts in 1993. The band is characterized by fusion of indie rock, emo, post-hardcore, post-rock and jazz, with the jazz influence becoming more dominant in later releases. Listen to them and you'll probably see the parallels.
There are a surprising number of emo bands that have sports-related names. I've identified over 140 as of now. Some of these bands, like American Football, Football, etc., Major League take their names from specific sports. Others, like Free Throw, State Champs and Losing Streak, use sports-related terms in a more general way.
There are a few possible reasons why emo bands might choose to use sports references in their names. One possibility is that it's a way to connect with their fans. Many fans of this genre of music are alienated from typical sports fans.
It's possible that the use of sports references in emo band names is a homage to the sports bands that came before them. Bands like American Football, Karate and Sweden's Tennis were pioneering a different sound in the 1990s, and they both used sports references in their music. It's possible that newer emo bands are paying homage to these bands by using sports references in their own names.
However, it's also possible that the use of sports references in emo band names is ironic. Emo music is often about feeling lost and alone, and sports can be a symbol of conformity and mainstream culture. By using sports references in their names, these bands may be poking fun at the idea of conformity and mainstream culture.
These bands come from different eras and styles of music, but they all use sports references in their names. I'm not sure where this journey will take me, but maybe we can figure out how this came to be.