**Whether it’s the Christmas derbies or Easter’s Judgement Day, there are guaranteed fireworks when the Guinness PRO14’s Welsh contingent go head-to-head.** There’s the grudge match in the south of the country, with no love lost between Cardiff Blues and Dragons, while further west brings a similarly intense rivalry between Scarlets and Ospreys. The clashes are equally fierce in any variant of the all-Welsh fixtures – just ask those who have played in them. Tom Shanklin and Shane Williams have done so on plenty of occasions for Cardiff Blues and Ospreys respectively and this week gave an insight into their derby experiences ahead of the latest encounters, on which both will be offering their expert opinion for Premier Sports.