Abstract: Portable safety system for isolating an on-deck batter during a baseball or softball game comprises one or more poles, a length of cord long enough to surround an on-deck area, structure to support the cord and a fastening system for fastening the ends of the cord to the poles or to each other. The safety system may be free-standing and entirely supported by poles, or partly supported by a backstop commonly found on baseball fields in addition to one or more poles. The poles may have holes, brackets, a spring loaded roller, or part of a hook and loop system to support the cord. The fastening system comprises hooks, hook and loop material, or similar structures. The poles also contain structural elements to help in securely wrapping the cord around the poles for storage and transport. The safety system is lightweight, portable, inexpensive, and easy to assemble and disassemble.