In the old BTM, Core Torque used to mean exactly what you said and thought:
the higher the number, the more skid/flip (hockey stick shape) the breakpoint was. The lower the number the more even and arc-like it was (Think sanded urethane ball path). 4-5 was urethane like hook. 6.5, at that time the highest number, was a skid/flip pearl resin. Today 5.5 seems ot be the low number and a few balls are as high as the Cell Pearl's 7.5 (Big Shot, Fired-Up, Big-R-Bang, World Class Reactive, No Mercy Beat'n, Break Pearl).
If you read the notes, some balls, currently with a Core Torque number of 6.5, are described in the written text as NOT being skid/flip, while some with 6.5 are described as skid/flip.
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