1 – The number worn by the defending champion's caddie on the left breast pocket. Steve Williams, Adam Scott’s caddie, wore No. 17 last year and will wear No. 1 this year. Numbers above 1 are distributed to caddies in the order in which participants register during Masters Week.
5 – The record number of victories by one caddie, shared by Willie “Pappy” Stokes and Willie Peterson. Stokes worked for Masters champions Jack Burke Jr., Claude Harmon, Ben Hogan (twice) and Henry Picard. Peterson was on Jack Nicklaus’s bag for the first five of his record six titles.
90 – When Jack Nicklaus returned in 1966 to defend his 1965 title, he refused to accept the No. 1 caddie number given to the defending champion. He chose the No. 90 that caddie Willie Peterson had worn the year before. “A No. 1 has never won this tournament, you know,” Nicklaus said the week before the 1966 Masters as he went through his usual pre-Masters week practice routine. “The fact of no repeaters doesn't bother me; really it doesn't make one bit of difference. I would just like things to be like last year.” It was, as Nicklaus became the first player to win consecutive Masters, a feat since repeated by Nick Faldo (1989-90) and Tiger Woods (2001-2002).
1983 – The first year that Augusta National allowed players to bring their own caddies.
Yardage books – The Augusta National Golf Club golf shop provides the yardage books for the course. Typically, one is given to the player and one to the caddie. Yardage books were likely first distributed to the participants in the mid-1980s.
Caddie uniforms – The caddie jumpsuits first worn by caddies in 1946, the first Tournament following World War II, were made of a heavy, hand-sewn, herringbone material. Prior to that caddies usually wore clothes similar to the style of the day, even though pinned-on numbers to help fans recognize players were used beginning in the early 1940s. Today’s jumpsuits are made of a lighter material that is wrinkle resistant. Each player’s name (on the back), number and Augusta National logo (on the front) are Velcroed onto the uniform. Each suit is washed nightly.