It could be the right-handed bowlers playing on your side of the lane. If the
shot is also inside for them, they’ll constantly be moving in deeper, and eventually
dissipate the lane conditioner on the left side leaving you with no lane conditioner
to create the required skid in the front portion of the lane. Solutions: Move to the
outside portion of the lane where there’s less play, or switch to a ball that
creates less friction.