I know zilch about golf. But I was flipping channels, and they were re-playing a great shot by Tiger Woods, so I watched for a bit.
On his second shot of,say, a 400 yard par 4, the commentator said something like “great shot–he has only 153 yards to the green”. Then on the green, he said “that leaves him a 19 foot putt for birdie” . Then they showed a graphic on the screen listing his previous putts, such as “9 feet 7 inches”.
How do they make those measurements? They seem to be in real time, because they announced the 153 yard and the 19 foot distances almost as soon as the ball stopped rolling. And how to they get the precision to inches?
They use sophisticated combinations of GPS and computer programs that have the dimensions of the hole and the green already figured. Then they spot the ball optically, using the camera feed, which allows them to know where it is in relation to the hole, which they also have a precise location for, and the tee markers (which they ALSO have precise locations for). It’s relatively new, and it’s fun, because before that, all you had was the guess of the announcers, and I can’t tell you how often an 8 foot putt was described as being at LEAST 15’! 
If you watch after a player’s drive, you might see one of the TV flunkys standing near the ball; that person will be providing the network with a general positioning of the ball, they stand beside it so that the distance from the tee can be determined.
The funny part? The players’ caddies often can be just as accurate as to distances to the hole using only their strides and their yardage books. :eek:
The system is called Shotlink.
Not only that but the players and caddies have played most of the courses before many times. The know the distance from numerous landmarks down to a gnats eyelash.
One of the main differences between expert golfers and we dubs is that they know how far they hit each club and are able to do it time after time.
Yes, I noted in the Tour Championship that Tiger had it down to a VERY exact science. I’d say his distance is accurate to within +/- 2 yards from inside of 200. :eek: