[JaredL]

I'm not going through and reading the whole thing but I don't think the US players would have much of a chance. They would probably be better than the US national team though.

For full disclosure, I'm sure I know more about rugby than the average American, but I still don't know that much about it. Most of I watched 3 or 4 matches from the 2003 World Cup with a friend who is a big fan and explained what was going on.

In addition to not having enough of a tactical understanding - something that is pretty devastating since the game is free flowing with few if any set plays by a coach - the NFL guys would have to change their exercise regime. The same would be true the other way. The difference is that rugby involves a lot of running (both jogging and sprinting) with tackling as well as some stoppages for kicks, line-outs, and scrums. This is quite different than (American) football which features short plays that are essentially at full effort with breaks in the middle.

This difference has caused football players to develop bodies for that type of game. They are very explosive, being both ridiculously strong and quick for their size. If you could sub the whole team on for a scrum near either goal line you would probably want the NFL guys over the rugby guys. The problem is stamina. I think the NFL players would get worn out and would be destroyed in the late stages of any game they played. They could improve this in 6 months, but I don't think by enough to overcome it especially as they will need to spend a lot of time learning the game.

I don't think comparing the two is like comparing an sprinter and a marathoner since they aren't that different but it's like giving Asafa Powell a couple months to train to beat Jeremy Wariner in the 400 or Gary Reed in the 800.

The reverses obviously holds too. I think a team of the rugby players best suited for the NFL would be dogs to a good college team if they had a year or whatever to train.