Is the benchmark ball:
A. The ball you throw first on fresh oil, arch, rolly, control ball?
B. The ball that is a medium reaction (you have earlier arcing ball and later sharper ball?
These 2 are different for me. Not sure everyone has the same definition of benchmark...
For me, a definition IS the thing being described. It is not an opinion.
Unless you're blind, you can call a red rose blue. That is not what "red" is defined to be; it is not an opinion.
A benchmark ball is not necessarily the ball you use in your regular league.
For your release (and a benchmark can vary wildly, depending on your release, speed or rev dominance, and all the usual factors), the benchmark ball is the one that gives your an arc-ing, control type of reaction on medium oil conditions. The benchmark allows yo to judge its reaction on a lane condition that you know nothing about. It's a test ball; so to speak. It helps you define the oil pattern for your release and lets you determine what is the best ball in your arsenal to score well on this unknown oil pattern.
For some people that benchmark could be a Warrior, a Grudge, a Scandal or a Cyclone or a Tropical Storm or anything in between.
If your favorite ball goes 50 feet and makes a left turn on your house pattern, that is not a benchmark ball. It may be your favorite ball, but it sure a heck ain't a benchmark ball.