Slope.
Generally speaking, most golfers utilize a GPS with slope to be able to find the true yardage to a green, whether elevated or down the hill from your hitting position. However, in today’s blog, here is the reason why you should account for slope. Here are 3 shots with a 6 iron, with all mid trajectories. Assume centeredness of contact, angle of attack to the ball, and face angle are all the exact same. All we are concerned about here is how the elevation of the fairway of the green is going to affect your shot.
The first shot is the normal, level playing conditions. If you know your 6-iron carries 174 yards at your normal swing speed of 88 mph for an iron, then this is what we see.
Now the second illustration show the slope to be 50 feet higher than level. An elevated slope means that your carry is going to lose 19 yards distance, solely because of the elevation. Additionally, the descent angle is now 34°, meaning you can expect the ball to roll out more when it lands. Also notice that the height of the shot remains the same.
Finally, the last illustration shows downhill 50 ft. This means that same club, same swing, same speed, you can expect the ball to carry 189 yards-and additional 15 yards longer, with a descent angle of 52°, meaning when that ball lands, it’s going to want to bounce and settle.
So, with slope, if each club has 4° variation between themselves, and that’s roughly 8-12 yards between clubs, that means if you are hitting to and elevated green, you’d be wise to club up some. Likewise, if you are hitting down a hill, you’d be just as wise to take a club or two away. Obviously other factors like wind, lie, and temperature come into consideration, but slop is usually overlooked.
Each club being 8 yards difference, an elevated green at 50 feet would be roughly 16-19 yards, so club up two clubs. Likewise, if you are downhill, at 50 feet, take two clubs away. One club added then for 25 feet elevated or dropped for downhill. Your contact and swing speed all determine distance, so don’t consider this gospel, but do consider taking more club for uphill shots, and less club for downhill shots.
If you’d like to learn more about the science behind these types of situations, sign up for Trackman University and utilize their free lessons
-David