There are numerous variable in lane surfaces than could explain it.
Most of these difference can be traced to the backend of the lane.
Since th USBC allows a tolerance on the depth of the channels, one
center could have deeper channels than the other. Also, the sidewalls
(kickbacks) could be more solid in one center. A more solid kickback
will create more pin action off the sides. Also, the pindeck could be looser
in one center, again creating more or less pin action from one to the
other. All of these factors impact the pin carry and, ultimately your
average.