Just how big are these Welsh backs?

Wales have a big back line. A very big back line. Ireland have a small back line. Very small by comparison. But just how much bigger are the Welsh players than their Irish counterparts? Take a look at these examples:

Starting at fullback, Rob Kearney is the only Irish back who's heavier than his Welsh opposite number. At 95kg he's got the weight of a decent bag of potatoes over Leigh Halfpenny (85kg).

But that's as good as it gets for Ireland. Rob's brother Dave Kearney (91kg) concedes the weight of a full butane canister to Alex Cuthbert, who weighs 106kg.

Brian O'Driscoll (93kg) will have to contend with Scott Williams (100kg). The difference of 7kg is the same weight as the brain of a Sperm Whale.

The biggest weight deficit that Ireland face in the back line is between Gordon D'Arcy at 91kg and Jamie Roberts at a huge 110kg. The difference between the two men is the equivalent of 3 fully-grown Jack Russell Terriers.

Andrew Trimble (97kg) finds himself with the mammoth task of marking Wales' star man George North (108kg). The 11kg difference is the same as a hardback 17th Century King James Bible. Let's hope Andrew's said his prayers before North runs down his channel.

Johnny Sexton (92kg) and Rhys Priestland (95kg) are the closest in weight across the backlines. Hopefully Johnny can get his hands on the 3kg Six Nations trophy to even things up.

Lastly the match will feature two of the bigger scrumhalves in European rugby, Conor Murray (94kg) and Mike Phillips (101kg). Phillips is heavier by the weight of five bottles of wine, something he's very familiar with if rumours are to be believed...