Putters, Inserts, Grooves, Ball Roll and Face Milling

Recently, there has been more and more talk about the importance of an optimal 'ball roll'. 'Groove Technology' is supposed to result in a better 'ball roll' . There are, however, no physical principles that actually support these theories. It goes without saying that grooves on the putter face create a modified feel for the putt, but this is not a ground-breaking new development.

Grooved and Non-grooved Putter Faces

We will now try to illustrate the differences between grooved and non-grooved putter faces.
The truth with regard to whether one or the other technology is better is likely to be somewhere in-between. Countless videos of putter comparisons can be found on the internet . High-speed cameras are used to suggest to the consumer that grooves are able to make the ball roll more quickly or even give it top spin. This theory cannot be proven physically, as the ball roll is not influenced by the grooves, rather by the dynamic loft at the moment of impact.

In order to produce a 'true' putt, the roll of the ball should be initiated as early as possible. Putters with too much dynamic loft initially send the ball through the air after the moment of impact and the actual 'roll' is only initiated after the ball has touched the ground again. While the ball is in the air, hardly any ball rotation can be observed. This is referred to as the 'gyroscopic effect'. The gyroscopic effect is the self-controlling effect inherent in the ball due to the rotational motion of individual elements or of the whole system. This is not only a stabilisation due to the moment of inertia, rather a complex of dynamic operations that can return the ball to a stable state even in the case of minimal irregularities.

The effect can be clearly observed on a bicycle tyre that is rolled on a horizontal surface. The tyre rolls more or less straight ahead for a surprisingly long time. A torque that would make the tyre fall over exerts precession on its rotary motion, which means it rotates around the vertical axis. As this rotation takes place in the same direction as the falling direction (if it falls to the right, it also turns to the right), the tyre steers itself. This effect does not last forever. If the rolling speed drops below a certain value, the tyre ultimately falls over.

The same thing happens to a golf ball. The angular momentum keeps the ball on line provided it is not influenced by any other forces exerted on it. As already mentioned, the angular momentum only arises when the ball starts to rotate on the ground from its trajectory after the moment of impact. Consequently, the so-called 'hang time' or 'skidding', i.e. the time the ball spends or distance it travels in the air, should be minimised as much as possible. Alongside the greater running smoothness of a ball that rotates at an early stage, these putts will also roll further with the same energy transfer than putts that are in the air for longer.

Caledonia Groove Technology

We ommit the use of glued in face inserts. Through time intensive surveys we have developed different groove technologies to cover he complete range of impact feel and ball roll.

Caledonia Cross Groove


The R&A (Royal and Ancient Golf Club of St. Andrews) conforming Caledonia-Cross-Grooves reduce the impact area to a minimum. The precision milled grooves absorb vibrations at impact and create an extra soft feel.

Caledonia Horizontal Groove


The R&A (Royal and Ancient Golf Club of St. Andrews) conforming Caledonia-Horizontal-Grooves produce a soft but still solid impact feel. The energy transfer at impact is a little higher compared to the Caledonia-Cross-Grooves although vibrations are being absorbed noticeably.

Plain Face Groove


The precision milled non grooved face provides maximum energy transfer - preferred by players with a short backswing and who are used to a crisp impact feel.

QUESTION: what influences the roll of a putt?

ANSWER: the dynamic loft at the moment of impact!

(The dynamic loft is the measured loft at the moment of impact;
the static loft is the measured loft of the club in a resting position)

It makes sense that a putter with high dynamic loft results in a higher trajectory of the ball compared with the trajectory of a putter with low dynamic loft. Most putters you can buy in a pro shop have 3, 4 or even 5 degrees of static loft . If this were to be reduced to 1 degree, the 'hang time' would be shorter and it would make the ball rotate considerably earlier. Most putter heads with grooves are already produced with lower static loft in order to force an earlier roll.

So if grooves do not influence the actual roll, the question arises as to why the principle of groove technology is still applied. In many cases, grooves and putter face inserts can alter the subjective ball striking feel. Particularly in the case of putters manufactured with low-cost raw materials and a minimum of production overhead, grooves and inserts can be helpful. In the case of putters that are CNC precision-milled from a solid block of stainless steel or very soft alloys, additional components such as inserts are usually not required. Many companies make their putters by casting low-cost stainless alloys. Molten metal is poured into moulds and plastic inserts are embedded in the putter face to create a playable face. These inserts are usually bonded and this imprecise manufacturing step means they have high tolerances. It is often the case that two putters manufactured in the same way feel completely different. The sound pattern at the moment of impact is also very different in many cases.

Putter manufacturers who require that their production process meets a high standard would never deem cast clubheads to be high-quality products. The best raw materials, combined with precise and correspondingly time-consuming milling processes, guarantee the best quality and maximum playability. Clubheads that are precision-milled from soft, high-quality and correspondingly cost-intensive material feature a pleasant feel at the moment of impact. This subjectively soft feel can be enhanced by grooves on the clubface.

Nowadays, people refer to 'aggressive' or 'deep' grooving. The clubfaces are given deep grooves to reduce the contact area of the ball with the clubface. Vibrations that can be transferred at the moment of impact from the clubhead through the shaft to the hands can be reduced with this technology. Furthermore, the sound at the moment of impact is muffled. In this case, many golfers talk about a soft playing feel. Whereas grooves do not change the actual roll of the ball, these technologies can certainly influence putting. Self-confidence when putting arises from repeatable specifications at the moment of impact with results that can be anticipated. Grooves can enhance the subjective feel of a well struck ball, thus significantly increasing self-confidence through the certainty that the stroke has been executed correctly.

Alongside the playing characteristics that are relatively easy to alter, as far as the subjective feel of the moment of impact is concerned the putter must be 'tailored' to each player. From our point of view, clubface balance, swing weight, shaft length and grip size are equally important indicators with regard to achieving good putting results. With professional fitting and the integration of digital tools such as Putt Labs (Zenio, Sam Putt Lab, etc.), it would be negligent to play just any old putter off the shelf without knowing which putter actually fits. Very few putter manufacturers want to deal with the issue of clubhead balance, because mass production of tailored putters is quite simply not possible.