Despite disliking golf, I can’t seem to stop thinking about it.
Today’s invention is a camera system which sits atop the flag at a green and makes a panoramic movie of the area within, say, a 10 m radius. It also records temperature and relative humidity (if these are relevant to the dynamics of putting).
When a ball drops into the cup, the last 20 seconds of action on the green and relevant environmental data are stored. Some of this footage will show putts, from a range of distances, which were successful.
Over time, a huge number of these trajectories is stored for each green. For training purposes, players can later access, via a handheld device, a view of the green indicating the path which they should attempt to make their ball follow from its current location.