The old conventional wisdom is that shorter pins are earlier and more even while longer pins go longer and are more angular.
Whether that's true anymore is anybody's guess.
I think a better way to think about it is that longer pins, in the interest of making static weights easier to manage by keeping the CG close to the midline, tend to get laid out with the pin higher, promoting length and a more angular reaction.
Conversely, balls with short pins tend to get laid out with the pin lower, again, promoting an earlier and smoother reaction.
SH