I recently bought a rangefinder with slope function. My first inclination was to spend $400, but as I checked the reviews, I found players saying straight distance accuracy is within a yard or two with cheaper brands. On an impulse, I bought a model under $250. As far as slope function, there were no comparisons between different brands. Surely each manufacturer must discuss their slope function formula, right? Nope! Only Bushnell even mentions it, stating they consulted renowned tour caddy Don Thom for his formula to adjust yardage readings for slope. I have no idea who that is, but realized their method was proprietary.

In another thread I asked if anyone knew the formula used in the device I just purchased. To my surprise, the manufacturer replied saying the height of a shot does not change the "metrics" because the distance and elevation change are constant. That reply is nonsense. Either he does not have a real answer or he was deflecting an important question.

Golf shots travel in an arc, not a straight line. The ball rises and then falls, so the height of the arc is critical to estimating carry distance to another elevation. The landing will depend on the height of the ball along the arc when it intersects the slope. Therefore, two players, A and B, with the same distance on a flat approach can have very different yardage playing to a slope if the height and arc differ. You could also apply it to the same individual using two different clubs that normally give him the same yardage but different trajectories.

I now question the usefulness of slope function from manufacturers who do not define their "corrected" or "adjusted" yardage. There must be differences for men and women, seniors and juniors, high-handicappers and low-handicappers. Any thoughts or real comparisons of devices?

Example of the issue below:

In another thread I asked if anyone knew the formula used in the device I just purchased. To my surprise, the manufacturer replied saying the height of a shot does not change the "metrics" because the distance and elevation change are constant. That reply is nonsense. Either he does not have a real answer or he was deflecting an important question.

Golf shots travel in an arc, not a straight line. The ball rises and then falls, so the height of the arc is critical to estimating carry distance to another elevation. The landing will depend on the height of the ball along the arc when it intersects the slope. Therefore, two players, A and B, with the same distance on a flat approach can have very different yardage playing to a slope if the height and arc differ. You could also apply it to the same individual using two different clubs that normally give him the same yardage but different trajectories.

I now question the usefulness of slope function from manufacturers who do not define their "corrected" or "adjusted" yardage. There must be differences for men and women, seniors and juniors, high-handicappers and low-handicappers. Any thoughts or real comparisons of devices?

Example of the issue below:

**Edited by Blindkarma, 19 August 2017 - 07:43 PM.**