If you’re uncertain on which way a green breaks, learning how to plumb bob a putt could really help you get it right and become a green-reading master. But you need to understand how the plumb bob should work and how to put it into practice correctly on the golf course.

Here below, we give you the information you need on how to plumb bob a putt...

What is a plumb bob

A plumb bob is a tool that was historically used to establish a vertical or plumb line, it’s a method that is known to have been used at least as far back as ancient Egypt. The tool was generally a pointed weight on the end of a string and was used in building to ensure walls were being constructed vertically – An earlier form of a spirit level.

In putting, the idea is that you replace the plumb line with your putter to plumb bob and determine whether the line of your upcoming putt slopes to the left or right. It can work, but only if you do it correctly.

Check your putter

In order to plumb bob effectively, you have to check the shaft of your putter hangs absolutely vertically when you hold it lightly between thumb and forefinger on the grip.

It likely won’t do that automatically as the shaft will generally not go into the very centre of the head meaning there will be some tilting. Find a known vertical, like the edge of a building, and hold the putter up so you can compare the vertical with the shaft lean.

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Twist the putter round between thumb and forefinger to find the point where shaft and the chosen vertical are level. Look where the putter head is positioned and remember that.

This is very important as it’s how you must hold your putter each time in order to have a true vertical line when plumb bobbing – It won’t work otherwise.

Take it to the putting green

You need to gain a good understanding of how the plumb bob method works before you put it into practice on the course, so you should spend some time on the putting green learning the process.

Get behind it

Stand about 10 feet or so behind the ball (maybe further back for longer putts) so you are looking directly through the ball to the hole in a straight line. Close one eye and use your dominant eye.

Hold the putter up, as described above between thumb and forefinger, towards the end of the grip if you can, covering the ball with the shaft. If the shaft also covers the hole, the putt should be straight – the ground you are standing on should be level. 

If the shaft appears to the right of the cup, the slope you are on should take the ball from right to left. If it appears to the left of the cup, the slope should take the ball from left to right.

A useful guide

Remember the plumb bob may be a useful guide if you’re not sure on a subtle slope but it’s not a given, and it also won’t help you determine if the putt is up or downhill.

An alternative

You may use the plumb bob just as a guide against the horizontal contours of the green. If you kneel and have the putter hanging vertically, you can observe how the contours of the green cross the shaft.

If they do so at right angles, the green should be flat, and any slopes left to right or vice versa should be easier to make out.