Six Nations up for grabs as 'cousins' prepare for battle

Any rugby rivalry sufficiently intense to generate the gratuitous violence that scarred the England-Wales game at Twickenham in 1980 - not to mention the 1987 bloodbath in Cardiff- has the potential to boil over, even in an age of union sanitisation. It just boils in a different way, as Billy Vunipola and Taulupe Faletau are likely to demonstrate when the Six Nations title effectively goes up for grabs this afternoon.