You might want to file this under the “Hardcore Golfer” category but some people like to get down and find out which way the grass on a green is growing before they putt.
The theory, I suppose, is that grass growing towards the hole will make the ball run faster to the cup. Then the opposite would be true for grass growing away from the hole. Your ball will travel slower on its path.
There are hundreds, if not thousands, of tips and tricks people suggest and try for putting. I’m not personally sold 100% on this grass direction idea but if you’re struggling with your putter it might be something to check out for yourself.
Just don’t get caught on your hands and knees inspecting grass growth patterns in front of your good friends. That sounds pretty embarrassing.