If you take a close look at the illustration provided by Bob, you will see that only the GEC is run back to the Service panel. Notice how the rest of the 'connections' are bonded to the GEC, using the different electrodes as connection points.
This helps to reduce if not eliminate the parallel paths.
Those conductors that are bonded to the GEC are not Grounding Electrode Conductors, they are bonding conductors.
Pierre
