What is the standard way to do it? Straight tape? With the curve?

Straight tape seems pretty self explanatory. I've seen diagrams on the internet scoring blackbuck by measuring the horns with a tape basically hugging the the same side (e.g. outside) of the horn all the way up - not going around the horn. That way I guess you get the full length of the horn, which might vary differently from straight tape depending on just how deep that animal's curves are. Is that the way to measure it? I.e., you don't follow the curve around the horns all the way up?

Many thanks for any input.

Straight line is the standard. Straight up the front or side. Some folks like to measure along the curve to stretch the tape, but I don't know of any scoring system that goes around the curve, nor are you comparing apples to apples when going around the curve.

When on the hoof guides usually judge them straight tape.

As for how you want it measured it all depends on which scoring system you like. I think ROE may do straight tape but I don't really pay much attention to that scoring system anymore. I think you take two circumferences.

TGR and SCI score them for record book status differently with the measurements taken around the horn. Circumferences are also taken.

You can easily have a 19" straight tape blackbuck out score a 21" straight tape blackbuck with the mass differences and the degree of twists that the horns make. It happens all the time. I had a 19" one this year that went Gold and another 21" that was barely a 3 twist but was only a Bronze because of its mass and twist.