The optimum placement is as close to the connector as possible.
EMI during an ESD event can couple from the trace being struck to other nearby unprotected traces, resulting in early system failures.
The PCB designer must minimize the possibility of EMI coupling by keeping any unprotected traces away from the protected traces which are between the TVS and the connector.
Route the protected traces as straight as possible.
Use rounded corners with the largest radii possible on the protected traces between the TVS and the connector, thus eliminating any sharp corners.
Electric fields tend to build up on corners, increasing EMI coupling.
If pin 1 or pin 2 is connected to ground, use a thick and short trace for this return path.