Trackman Essentials Pt.1: Distance (Pt.2)

Welcome back to the following part of the previous post. If you have not read Trackman Essentials Pt.1: Distance (Pt.1), I would highly recommend going back and reading that if you are not already familiar with basic definitions regarding this topic. If you have read the previous post, this post will expand on the ways that the different elements (covered in last week’s post) combine to create distance.

Club Head Speed

I’m sure you can work out that the higher the club head speed, the further the ball will travel. This is only true if ceteris paribus (all other factors remain constant). As a general rule of thumb, 1mph of club head speed equates to roughly 3 yards of distance. However, this rarely manifests itself in the real world, as most PGA tour players have swing speeds >115mph, and very few of them reach 345 yards. This is due to the other factors that will be mentioned shortly.

Attack Angle

If the attack angle increases ceteris paribus, the ball should travel further due to the decreased spin loft. However, an increased attack angle rarely results in ceteris paribus, so it often results in many other problems, usually an increase in effective loft, which is usually detrimental in value. Additionally, having a high attack angle will result in a lower impact height, which has its own complications.

Dynamic Loft

Increasing the dynamic loft will result in a higher peak height (ceteris paribus), which will usually result in a lower distance. Additionally, a higher dynamic loft will result in a higher spin loft which usually causes other complications which we will get into later. Moreover, a high dynamic loft can result in a lower impact height which is not a good thing. However, increasing the dynamic loft can result in further distance if the player is de-lofting the club face to an excessive degree, but often the opposite is more commonly found.

Spin Loft

Increasing the spin loft will (usually) reduce distance. This is because the main effect spin loft has is directly proportional to the spin rate. Again, increasing the spin loft could result in further distance if the player is de-lofting the club face to an excessive degree, but the opposite is more commonly found. Dynamic loft and Spin loft are proportional to each other.

Spin Rate

The graph of spin rate against distance is essentially a bell curve, as it is for many of these factors. There is an optimum spin rate which varies from club to club, but the majority of golfers find themselves to be way past the optimum. For wedges, any additional spin the golfer can gleam will be helpful. For irons, the optimal spin rate tends to be the club number multiplied by 1000. For example, a 9-iron should spin at 9000, an 8-iron should spin at 8000 and so on. For a driver, Taylormade released a study which concluded that the optimum spin rate is 1700. However, this has been widely debated with many players aiming for a higher, more achievable spin rate. At the end of the day, the optimum spin rate depends on many other factors, so it can vary drastically from player to player.

Impact Height

Now this is a controversial topic within the golf community, as it has often been believed that the optimum impact height is 0. This means directly in the middle of the club face, exactly in front of the geometric centre of gravity. However, Trackman themselves have found a ‘hotspot’ for distance which we will discuss in the next few weeks. However, a correlation can still be made. A higher impact height will result in a higher dynamic loft, which will result in a higher peak height. Now, you may be thinking that because of the increased dynamic loft, the spin loft will also increase, and therefore the spin rate will also increase. However, due to a concept known as the ‘vertical gear effect’ (which is essentially the club trying to compensate for a mis-hit), the spin rate is lower the higher the impact height is. Vice versa, the lower the impact height is, the higher the spin rate is, and while some golfers will not admit to this, I can personally say with 100% confidence (based on personal experience), that a higher impact height will lead to a lower spin rate ceteris paribus)

Launch Angle

This is caused by other factors such as attack angle, dynamic loft and impact height. During Taylormade’s study into the optimum launch conditions, they found that the optimum launch angle is 17°, which again took a lot of golfers by surprise as it has often been said that the optimal launch angle is much lower at around 14°. However, (like Taylormade found) launching the ball at 17° while maintaining a spin rate of 1700 is a tall order, as it requires an extremely low spin loft and an extremely high attack angle. Most golfers will have a launch angle higher than optimum.

Ball Speed

This correlation should be obvious; the higher the ball speed, the higher the distance. This is true in all cases, as there is no such thing as a ball speed ‘too high’. Ball speed can be calculated using a ratio which is called ‘smash factor’. This is effectively the efficiency of the strike. The full formula for smash factor is as follows:

(1+COR of club face) / cos(spin loft)/(1+(Ball mass/ Clubhead mass))

Quite a mouthful? A simplified formula which gives a near perfect answer is simply:

Ball Speed / Club head speed

Much easier. The ‘maximum’ smash factor is 1.50, with the PGA tour average being 1.48. However, myself and many other players have seen smash factors northwards of 1.60, which is theoretically impossible, but life is full of surprises, isn’t it?

Height

Many coaches try to get their players to launch the ball high and spin it low, with the phrase ‘tee it high, let it fly’ being in popular usage. However I argue ‘tee it low, let it flow’ is just as memorable. Again, the graph for height against distance is a bell curve, or more appropriately, a golf ball’s trajectory, with the optimum height for a swing speed of 110mph being just under 100ft.

Land Angle

The lower the land angle, the more roll the golf ball will perform, which will result in a higher total distance. However, to create a low land angle, the peak height must be low, which can harm carry distance. However it is fair to say that any land angle more than 50° is not going to maximise distance gains.

As it can be gleaned, there is a lot of interdependence between variables, and it is almost impossible to change one factor without changing any others.

Hopefully this entry has been engaging & informative, and I’ll see you next Sunday, with another less dry post. Bye!