Munster versus Ulster is a rivalry that dates back to the foundation of the game in Ireland in 1879. Games between the two have occurred on an annual basis since the inception of the IRFU Interprovincial Championship in 1946. Since the beginning of the inter-provincials in 1946, Ulster hold a 52–37 advantage in overall wins, with ten draws. Additionally, since the inception of the Celtic League in 2001–02, Munster hold a slender 19–18 advantage in wins, with two draws in that time.