Ruddock's Wales sealed a clean sweep with a 32-20 win over Ireland in the Millennium Stadium in 2005 and the Ireland U-20s coach is tipping Declan Kidney's side to halt a run of three consecutive losses against the Welsh.
Ireland haven't beaten Wales since the Six Nations clash in Croke Park in 2010, and last won in Cardiff in the dramatic Grand Slam finale in 2009, but with Welsh coach Warren Gatland seconded to the Lions and his side on the back of a miserable autumn campaign, Ruddock believes Ireland have the edge.
"Wales have a number of injuries but I think the biggest thing is that they'll miss Warren Gatland so I fully expect Ireland to win," Ruddock said.
"There is a lot of continuity in the Ireland team and I think the other thing that is going to make a major difference is the confidence the Irish players should have after some very good performances in Europe, whereas the Welsh have struggled."
With Jonny Sexton's decision to move to Racing Metro, the IRFU have lost their first front-line player to foreign shores since Keith Wood.
And Ruddock believes that the talent drain that has dogged the Welsh regions in recent seasons has had a detrimental effect on the national side.
"There is a lot of talk in Wales asking if the regions are working and there are players leaving," he said. "It's a very unsettled base at the moment. And for them to be as focused as Ireland have been is difficult, so I fully expect Ireland to do a job, particularly after Ireland's performance against Argentina."