Short pin is a ball with a 0-2" distance between pin and CG. Long pins are 3" and up. The different terminology results from the fact that a short pin usually has the pin ending up under the fingers, while a long pin offers you a pin above the fingers (in both cases CG in the palm area for legal static weights) and limits drilling options. If you wnat a certain reaction, a longer pin distance is just the better basis to work with.
I think the terms were established when the first cores with higher differentials were introduced. In the era of the urethane Hammers and pancake cores, pin distances used to be in the 0-2" range, and label layouts very common.
The longer pins and more powerful cores (with stronger internal weight shifts, depending on the core's placement upon pouring) offered much more drilling options, hence the term.
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DizzyFugu - Reporting from Germany
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