It is the national sport in the country where it is practised. To an extend it is also practised amongst the diaspora from this country which (apart from emigration) is large because the borders were once far more extensive.
I can give you that Fez It is Turkish oil wrestling (they massage each other with olive oil before a bout so they that can't get a firm grip of each other - which is why they try to grab onto the interior of the trousers of their opponent !) - they're not wearing anything other than leather trousers. Winning is considered to be when your opponents belly button is facing the sky. The national championship is held in Edirne and has been held there every year since 1362 making it the longest continuously held sporting event in one venue World wide. All of which means that you have to get your thinking cap on for the next one
Simple one then - Which is the odd one out, and why: Brazil, Uruguay, Argentina, Chile, Paraguay, Peru?
I hadn't considered that... but it's not the answer I'm looking for... but you're on the right lines.
So far we have had: an alternative answer but not the one I'm looking for; the right reason but the wrong country and the right country for the wrong reason... it is purely a geographical question.
The country that links the answer does have navy and is geographically similar to Paraguay in terms of its borders and location - they lost a war to Chile and their coastline with it. Amazing what you can pick up from QI. Given it away now...