First there is a different tournament green speed for Legends and Tour Masters so you have to define which you are playing on. I use 70% of the distance on a level putt, a 20 foot putt needs to be hit 14 feet to go the proper distance. However I have learned after about a year of play that on WGT a putt hit firm enough to go 2 feet by the hole is the proper speed to play your putts.