Vernier acuity isn’t the latest French golfing prodigy. It is the ability to detect misalignment amongst parallel line segments. Put plainly, it’s why stripes can help you putt better.

Get perspective

Imagine a long straight road – or runway. The farther you look down it, the more it appears to get narrower, finally reaching a single point in the distance. If you could lay a six-foot striped piece of paper behind your ball and look along it, it would be much easier to accurately identify your target. Set your ball up in the same alignment and away you go.


Ray Barret, a keen golfer and entrepreneur, had eye issues as he got older and started drawing different coloured parallel lines on his golf balls to see it better in the air. Instead, he found that using these lines on the green improved his putting.

This led to scientific testing by Dr. Carl Bassi from the College of Optometry at the University of Missouri. Bassi found that vernier acuity can help to increase putting accuracy by around 12 percent. That may not sound like much, but 12 percent off 36 putts could take 4.32 shots off your score. With a little bit of practice, you could improve your putting by up to 20 percent. And now we have the Callaway Triple Track ball and putter systems, and others hot on their tail too. See Callaway’s description of vernier acuity here:   (Please note that PuttBANDIT has no connection with Callaway — we only mention them because they have a great explanation on their web site.)

The line debate

There’s a lot of debate about the use of lines on golf balls. Purists say it’s not in the spirit of the game – taking some of the skill out of golf.  Perhaps, these are the same people who now are happy to play with the 460cc drivers we have today, rather than the 200cc drivers of years gone by. Golf has benefited from incredible technological advances over the years, which have made the game a little easier and encouraged much wider participation. That can’t be a bad thing, can it?

Equipment rules

So why don’t we all carry around six-foot-long striped devices to line up our putts? Because in golf we are (quite rightly) restricted by equipment rules. So the length of lines are set by a) by the size of the golf ball and b) in PuttBANDIT’s case, by having to be less than 5.08 cm (2 inches) in length, per the R&A equipment rules.


Golf is one of those sports with thousands of opinions, theories and techniques to help make us better golfers—many of which we’ve tried. But here’s one we can easily test. Keep track of your putting stats, how many per round, how many 3 putts, how much closer to hole for second, and so on.

Remember, lines will only help you aim more accurately. Stroke quality and speed are still down to you.

Play well

PuttBANDIT | Visibly Better Putting | Neil signature

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Neil Hart is a co-inventor of the PuttBANDIT Ball Marker, set up PuttBANDIT Ltd with brother Paul, and plays off 13.3.

PuttBANDIT Ltd is not in any way affiliated, endorsed by, or connected to other brands or websites that we may mention in our communications.