In 2019 there is one rule change you really need to know and use.
When putting you have 3 options:
1. Remove the pin completely
2. Have someone tend the pin
3. Leave the pin in and unattended (no penalty - formerly two strokes or loss of hole).
It’s a major change to speed up play, but years ago golf data expert - Dave Pelz - proved that by leaving the pin in you'll sink more putts - nevertheless, the USGA said there “should be no advantage in being able to putt with the unattended flagstick in the hole", but here are the facts:
Golf balls are 1.68” in diameter, leaving a .195”-gap of open space for the ball to fit into the hole with the flagstick in place. Doesn’t sound like much right, but Pelz tested it and showed conclusively that you should putt with the pin in!
His original Pin In/Pin Out test was conducted in 1990 and results published in the December issue of GOLF Magazine and in his book - the Putting Bible (we strongly recommend reading it) The results were conclusive.
You will hole a higher percentage of putts when you leave the flagstick in.
If there is any golfer who studies the physics of golf it's Bryson DeChambeau and in 2019 he plans on putting with the pin in. Our advice is you should do the same!