It is a number that has been reached just eight times in the long history of the PGA Tour, making it more rare than a perfect game in baseball.
Justin Thomas became just the seventh player to break 60 when he shot 59 in the opening round of the Sony Open in Hawaii. Jim Furyk has done it twice, shooting the all-time low round of 58 last year at the Travelers Championship after posting 59 in 2013 at the BMW Championship.
But when other players over the weekend, such as Kevin Kisner -- who missed a 9-footer on the last hole for a 59 -- and Chez Reavie also flirted with the number, it was cause for pause.