Time To Grow New Dendrites

[Bob Hartman]

This question may not be posed correctly.

How long in time does it take to grow a new working dendrite?

For example:  In billiards, if one is learning to stroke the cue stick
accurately,
and one practiced a moderately difficult shot for one hour daily, how
many days - months will it take to be 99% accurate.  That is to go
from consciously thinking yourself through the shot, to consigning the
shot the sub-conscious, because it is now hard wired.

Any insight will be appreciated.