Did Walter Camp invent American football? Most of the history books say yes, but the reality is much more complicated. American football began as rugby but quickly started to change the rules to make a better spectacle - just like many other rugby-playing regions. Discover how and why it changed in your ten-minute intro to the orgins of the gridiron game. For more on the history of rugby and the other football codes, follow me on Twitter @collinstony and at www.rugbyreloaded.com