 Complete the following phrase:  Despite the relative rarity of holes-in-one, there have been a total of six in Ryder Cup matches. Peter Butler scored the first in 1973 at Muirfield followed by a 20-year gap before Nick Faldo scored a hole-in-one in 1993. Two years later, Costantino Rocca and Howard Clark both scored holes-in-one before an 11-year gap to 