Originally Posted by Fourputt
What I'd like to know is how a launch monitor can possibly determine roll when that is completely dependent on the circumstances. Fairway cut, firmness, slope all have to factor in and no electronic estimate can get that right in any sort of realistic scenario.
That's a fair question
Amongst other things that determines ball roll out, decent angle, apex height, velocity, spin (or lack of) will provide a likely scenario of golf ball roll out distances. One thing to keep in mind that the difference between a "$20 a dozen distance Ball" and premium ball with the exact same data, will only be <7 yards. The LM assumes a flat fairway, some LMs will take into account rough which will reduce roll out distance but to hit in the rough you either have increased distance killing sides spin or a blocked shot. Keep in mind that a launch monitor is a data based scenario, it uses High tech "radar" to arrive at its accuracy and conclusion. For example a launch monitors only records the golf ball from impact to about 4-5 feet. Your variables, along with moisture, humidity, wind, side wind, elevation from sea level, fair way cut, hardness etc are not used.
Actually elevation above sea level might be used, I can't remember how I set my flight scope- all of my demos were at <1000 elevation so I may have set it as a default setting. I'm sure there are machines that do or will take into account of some of these factors. But because they are not used one could conclude that the testing data is consistent with any club, ball or player.
Obviously quite a bit of science and geometry goes in to these machines, but to totally discount the data because it does not take in you exact landing conditions does not change the likely hood of a consist measurement of roll out. I am using the exact same machine as the pros & manufacturers, functionality and data are the same. How you read the data and what you do with the data can be different. For most of us a total of 5-6 parameters are important for ball, club, shaft, for a golf ball manufacture it could 10-12 parameters they wish to look at.
although pretty rare I have witnessed a ball hit by a driver have negative roll out- in other words it spun back, as well as a worm burners and too low of launch drives that eventually rolls out close to 85% a normal drive by the same player.
I hope this helps