Yeah, one of his "big two" terms that say..."I'm an engineer, and you're not!"

Static Hysteresis and Virtual Mass.

I was under the impression that the lower the virtual mass, the greater the speed gain with lighter arrows. I do remember (back from when I used to read his reports every single issue) that the Mathews Z-Max had one of the lowest Average Virtual Mass #'s of any bow test I can remember. That bow definitely showed a bigger gain with lighter arrows than other bows of the mid-late nineties.

I really liked the test procedure he used, and he certainly has done and continues to do a great service to the archery industry in general. I wish I still had some of those old issues around to give Norb's own definition. I may still have one or two in the garage. I'll post again if I find the info.